1qx7

Crystal structure of apoCaM bound to the gating domain of small conductance Ca2+-activated potassium channel

Method: X-RAY DIFFRACTION D_max: 118.2 Å Quality: GOOD

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1. Protein Identity and Related Structures Protein Identity & Related Structures

Calmodulin

Rattus norvegicus

State in the Current Structure

Assembly	Oligomeric State	Construct	Mutations and Modifications	Ligands, Ions and Associated Components	Method and Experimental Conditions	Structure Quality
1	Protein homooligomer Homooligomer Protein × 2 PDB declaration: dimeric（2） Consistent with protein copy count	Chain I； UniProt 1–148 Chain R； UniProt 1–148	Non-standard monomer：Yes (specific site not provided by mmCIF)	No other associated polymer	X-RAY DIFFRACTION X-ray crystallization conditions：VAPOR DIFFUSION, SITTING DROP；pH 6.5；298 K；Citrate, NaCl, Hepes, pH 6.5, VAPOR DIFFUSION, SITTING DROP, temperature 298K	Resolution 3.09 Å R-free 0.308
2	Protein homooligomer Homooligomer Protein × 2 PDB declaration: dimeric（2） Consistent with protein copy count	Chain A； UniProt 1–148 Chain B； UniProt 1–148	Non-standard monomer：Yes (specific site not provided by mmCIF)	No other associated polymer	X-RAY DIFFRACTION X-ray crystallization conditions：VAPOR DIFFUSION, SITTING DROP；pH 6.5；298 K；Citrate, NaCl, Hepes, pH 6.5, VAPOR DIFFUSION, SITTING DROP, temperature 298K	Resolution 3.09 Å R-free 0.308
3	Protein heterocomplex Heteromer Protein × 2 PDB declaration: dimeric（2） Consistent with protein copy count	Chain M； UniProt 1–148	Non-standard monomer：Yes (specific site not provided by mmCIF)	Small conductance calcium-activated potassium channel protein 2 × 1 （P70604）	X-RAY DIFFRACTION X-ray crystallization conditions：VAPOR DIFFUSION, SITTING DROP；pH 6.5；298 K；Citrate, NaCl, Hepes, pH 6.5, VAPOR DIFFUSION, SITTING DROP, temperature 298K	Resolution 3.09 Å R-free 0.308
4	Protein homooligomer Homooligomer Protein × 3 PDB declaration: trimeric（3） Consistent with protein copy count	Chain A； UniProt 1–148 Chain B； UniProt 1–148 Chain M； UniProt 1–148	Non-standard monomer：Yes (specific site not provided by mmCIF)	No other associated polymer	X-RAY DIFFRACTION X-ray crystallization conditions：VAPOR DIFFUSION, SITTING DROP；pH 6.5；298 K；Citrate, NaCl, Hepes, pH 6.5, VAPOR DIFFUSION, SITTING DROP, temperature 298K	Resolution 3.09 Å R-free 0.308

Other States of the Same Protein in the Database

Each row is a biological assembly of the same UniProt protein in another PDB entry. The “Difference from current entry” column identifies evidence-level differences; no tag means the currently parsed fields agree.

Other PDB	Difference from Current Entry 1QX7	Assembly / Oligomeric State	Construct	Mutations and Modifications	Ligands, Ions and Non-polymers	Method and Experimental Conditions	Structure Quality
1G4Y 1.60 A CRYSTAL STRUCTURE OF THE GATING DOMAIN FROM SMALL CONDUCTANCE POTASSIUM CHANNEL COMPLEXED WITH CALCIUM-CALMODULIN Deposited 2001-01-07	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain R 2–149（148 aa）	Not recorded	SO4 SULFATE ION × 2 CA CALCIUM ION × 4	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.6；298 K；ammonium sulphate, lithium sulphate, citrate, pH 5.6, VAPOR DIFFUSION, HANGING DROP, temperature 298K	Resolution 1.60 Å R-free 0.251
1NIW Crystal structure of endothelial nitric oxide synthase peptide bound to calmodulin Deposited 2002-12-26	Different construct Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain A 2–149（148 aa）	Non-standard monomer：Yes (specific site not provided by mmCIF)	CA CALCIUM ION × 4 SO4 SULFATE ION × 1	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION；pH 5；298 K；Polyethylene glycol, ammonium sulfate, pH 5, VAPOR DIFFUSION, temperature 298K	Resolution 2.05 Å R-free 0.249
1NIW Crystal structure of endothelial nitric oxide synthase peptide bound to calmodulin Deposited 2002-12-26	Different construct Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 2 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain C 2–149（148 aa）	Non-standard monomer：Yes (specific site not provided by mmCIF)	CA CALCIUM ION × 4 EDO 1,2-ETHANEDIOL × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION；pH 5；298 K；Polyethylene glycol, ammonium sulfate, pH 5, VAPOR DIFFUSION, temperature 298K	Resolution 2.05 Å R-free 0.249
1NIW Crystal structure of endothelial nitric oxide synthase peptide bound to calmodulin Deposited 2002-12-26	Different construct Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 3 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain E 2–149（148 aa）	Non-standard monomer：Yes (specific site not provided by mmCIF)	CA CALCIUM ION × 4 EDO 1,2-ETHANEDIOL × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION；pH 5；298 K；Polyethylene glycol, ammonium sulfate, pH 5, VAPOR DIFFUSION, temperature 298K	Resolution 2.05 Å R-free 0.249
1NIW Crystal structure of endothelial nitric oxide synthase peptide bound to calmodulin Deposited 2002-12-26	Different construct Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 4 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain G 2–149（148 aa）	Non-standard monomer：Yes (specific site not provided by mmCIF)	CA CALCIUM ION × 4	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION；pH 5；298 K；Polyethylene glycol, ammonium sulfate, pH 5, VAPOR DIFFUSION, temperature 298K	Resolution 2.05 Å R-free 0.249
1NIW Crystal structure of endothelial nitric oxide synthase peptide bound to calmodulin Deposited 2002-12-26	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 5 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric	Chain A 2–149（148 aa） Chain C 2–149（148 aa） Chain E 2–149（148 aa） Chain G 2–149（148 aa）	Non-standard monomer：Yes (specific site not provided by mmCIF) Non-standard monomer：Yes (specific site not provided by mmCIF) Non-standard monomer：Yes (specific site not provided by mmCIF) Non-standard monomer：Yes (specific site not provided by mmCIF)	CA CALCIUM ION × 16 SO4 SULFATE ION × 1 EDO 1,2-ETHANEDIOL × 4	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION；pH 5；298 K；Polyethylene glycol, ammonium sulfate, pH 5, VAPOR DIFFUSION, temperature 298K	Resolution 2.05 Å R-free 0.249
1NIW Crystal structure of endothelial nitric oxide synthase peptide bound to calmodulin Deposited 2002-12-26	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 6 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric	Chain A 2–149（148 aa） Chain C 2–149（148 aa） Chain E 2–149（148 aa） Chain G 2–149（148 aa）	Non-standard monomer：Yes (specific site not provided by mmCIF) Non-standard monomer：Yes (specific site not provided by mmCIF) Non-standard monomer：Yes (specific site not provided by mmCIF) Non-standard monomer：Yes (specific site not provided by mmCIF)	CA CALCIUM ION × 16 SO4 SULFATE ION × 1 EDO 1,2-ETHANEDIOL × 4	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION；pH 5；298 K；Polyethylene glycol, ammonium sulfate, pH 5, VAPOR DIFFUSION, temperature 298K	Resolution 2.05 Å R-free 0.249
1NIW Crystal structure of endothelial nitric oxide synthase peptide bound to calmodulin Deposited 2002-12-26	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 7 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain C 2–149（148 aa） Chain G 2–149（148 aa）	Non-standard monomer：Yes (specific site not provided by mmCIF) Non-standard monomer：Yes (specific site not provided by mmCIF)	CA CALCIUM ION × 8 EDO 1,2-ETHANEDIOL × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION；pH 5；298 K；Polyethylene glycol, ammonium sulfate, pH 5, VAPOR DIFFUSION, temperature 298K	Resolution 2.05 Å R-free 0.249
1NIW Crystal structure of endothelial nitric oxide synthase peptide bound to calmodulin Deposited 2002-12-26	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 8 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain A 2–149（148 aa） Chain E 2–149（148 aa）	Non-standard monomer：Yes (specific site not provided by mmCIF) Non-standard monomer：Yes (specific site not provided by mmCIF)	CA CALCIUM ION × 8 SO4 SULFATE ION × 1 EDO 1,2-ETHANEDIOL × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION；pH 5；298 K；Polyethylene glycol, ammonium sulfate, pH 5, VAPOR DIFFUSION, temperature 298K	Resolution 2.05 Å R-free 0.249
1QX5 Crystal structure of apoCalmodulin Deposited 2003-09-04	Different mutation/modification Different experimental conditions Different structure-quality metrics	Assembly 1 Protein homooligomer Homooligomer；Protein × 2 PDB declaration: dimeric	Chain D 1–148（148 aa） Chain Y 1–148（148 aa）	Not recorded	No recorded non-water small molecule	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 6.5；298 K；Citrate, 150 mM NaCl, Hepes , pH 6.5, VAPOR DIFFUSION, HANGING DROP, temperature 298K	Resolution 2.54 Å R-free 0.277
1QX5 Crystal structure of apoCalmodulin Deposited 2003-09-04	Different mutation/modification Different experimental conditions Different structure-quality metrics	Assembly 2 Protein homooligomer Homooligomer；Protein × 2 PDB declaration: dimeric	Chain I 1–148（148 aa） Chain R 1–148（148 aa）	Not recorded	No recorded non-water small molecule	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 6.5；298 K；Citrate, 150 mM NaCl, Hepes , pH 6.5, VAPOR DIFFUSION, HANGING DROP, temperature 298K	Resolution 2.54 Å R-free 0.277
1QX5 Crystal structure of apoCalmodulin Deposited 2003-09-04	Different mutation/modification Different experimental conditions Different structure-quality metrics	Assembly 3 Protein homooligomer Homooligomer；Protein × 2 PDB declaration: dimeric	Chain J 1–148（148 aa） Chain T 1–148（148 aa）	Not recorded	No recorded non-water small molecule	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 6.5；298 K；Citrate, 150 mM NaCl, Hepes , pH 6.5, VAPOR DIFFUSION, HANGING DROP, temperature 298K	Resolution 2.54 Å R-free 0.277
1QX5 Crystal structure of apoCalmodulin Deposited 2003-09-04	Different mutation/modification Different experimental conditions Different structure-quality metrics	Assembly 4 Protein homooligomer Homooligomer；Protein × 2 PDB declaration: dimeric	Chain B 1–148（148 aa） Chain K 1–148（148 aa）	Not recorded	No recorded non-water small molecule	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 6.5；298 K；Citrate, 150 mM NaCl, Hepes , pH 6.5, VAPOR DIFFUSION, HANGING DROP, temperature 298K	Resolution 2.54 Å R-free 0.277
2HQW Crystal Structure of Ca2+/Calmodulin bound to NMDA Receptor NR1C1 peptide Deposited 2006-07-19	Different mutation/modification Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain A 1–148（148 aa）	Not recorded	CA CALCIUM ION × 4	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 4；277.15 K；7% PEG 6000, 5mM CaCl2, 100 mM sodium acetate, pH 4, VAPOR DIFFUSION, HANGING DROP, temperature 277.15K	Resolution 1.90 Å R-free 0.248
2MGU Structure of the complex between calmodulin and the binding domain of HIV-1 matrix protein Deposited 2013-11-07	Different construct Different mutation/modification Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain A 2–149（148 aa）	Not recorded	CA CALCIUM ION × 4	SOLUTION NMR NMR measurement conditions pH 6.3；308 K；Ionic strength (raw mmCIF value) 0.015；Pressure ambient NMR sample composition 0.1-1.2 mM [U-95% 13C; U-95% 15N] calmodulin, 0.1-1.2 mM MA8-43, 5 mM CALCIUM ION, 100% D2O \| 100% D2O	Resolution not provided
2PQ3 N-Terminal Calmodulin Zn-Trapped Intermediate Deposited 2007-05-01	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain A 2–77（76 aa）	Not recorded	CAC CACODYLATE ION × 1 ZN ZINC ION × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 6.3；277 K；100mM Na Cacodylate, 5mM Zn Acetate, 16% PEG8000, pH 6.3, VAPOR DIFFUSION, HANGING DROP, temperature 277K	Resolution 1.30 Å R-free 0.192
2PQ3 N-Terminal Calmodulin Zn-Trapped Intermediate Deposited 2007-05-01	Different construct Different mutation/modification Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 2 Protein homooligomer Homooligomer；Protein × 2 PDB declaration: dimeric	Chain A 2–77（76 aa）	Not recorded	CAC CACODYLATE ION × 2 ZN ZINC ION × 4	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 6.3；277 K；100mM Na Cacodylate, 5mM Zn Acetate, 16% PEG8000, pH 6.3, VAPOR DIFFUSION, HANGING DROP, temperature 277K	Resolution 1.30 Å R-free 0.192
2YGG Complex of CaMBR and CaM Deposited 2011-04-15	Different construct Different mutation/modification Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain B 1–149（149 aa）	Not recorded	MPD (4S)-2-METHYL-2,4-PENTANEDIOL × 1 TAM TRIS(HYDROXYETHYL)AMINOMETHANE × 3 CA CALCIUM ION × 4 MRD (4R)-2-METHYLPENTANE-2,4-DIOL × 1	X-RAY DIFFRACTION mmCIF provides none of the parsed conditions	Resolution 2.23 Å R-free 0.232
3B32 Crystal Structure of Calcium-Saturated Calmodulin N-Terminal Domain Fragment, Residues 1-75 Deposited 2007-10-19	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain A 2–76（75 aa） Fragment：N-Terminal Domain Fragment, Residues 1-75	Not recorded	CA CALCIUM ION × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.5；277.15 K；100 mM Na acetate, 0.01% Na azide, 21.25% PEG 8000, pH 5.5, VAPOR DIFFUSION, HANGING DROP, temperature 277.15K	Resolution 1.60 Å R-free 0.269
3B32 Crystal Structure of Calcium-Saturated Calmodulin N-Terminal Domain Fragment, Residues 1-75 Deposited 2007-10-19	Different construct Different mutation/modification Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 2 Protein homooligomer Homooligomer；Protein × 2 PDB declaration: dimeric	Chain A 2–76（75 aa） Fragment：N-Terminal Domain Fragment, Residues 1-75	Not recorded	CA CALCIUM ION × 4	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.5；277.15 K；100 mM Na acetate, 0.01% Na azide, 21.25% PEG 8000, pH 5.5, VAPOR DIFFUSION, HANGING DROP, temperature 277.15K	Resolution 1.60 Å R-free 0.269
3B32 Crystal Structure of Calcium-Saturated Calmodulin N-Terminal Domain Fragment, Residues 1-75 Deposited 2007-10-19	Different construct Different mutation/modification Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 3 Protein homooligomer Homooligomer；Protein × 2 PDB declaration: dimeric	Chain A 2–76（75 aa） Fragment：N-Terminal Domain Fragment, Residues 1-75	Not recorded	CA CALCIUM ION × 4	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.5；277.15 K；100 mM Na acetate, 0.01% Na azide, 21.25% PEG 8000, pH 5.5, VAPOR DIFFUSION, HANGING DROP, temperature 277.15K	Resolution 1.60 Å R-free 0.269
3BXK Crystal structure of the P/Q-type calcium channel (CaV2.1) IQ domain and CA2+calmodulin complex Deposited 2008-01-14	Different construct Different mutation/modification Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain A 2–149（148 aa）	Not recorded	CA CALCIUM ION × 4 SO4 SULFATE ION × 1	X-RAY DIFFRACTION mmCIF provides none of the parsed conditions	Resolution 2.55 Å R-free 0.267
3BXK Crystal structure of the P/Q-type calcium channel (CaV2.1) IQ domain and CA2+calmodulin complex Deposited 2008-01-14	Different construct Different mutation/modification Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 2 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain C 2–149（148 aa）	Not recorded	CA CALCIUM ION × 4 SO4 SULFATE ION × 2	X-RAY DIFFRACTION mmCIF provides none of the parsed conditions	Resolution 2.55 Å R-free 0.267
3BXL Crystal structure of the R-type calcium channeL (CaV2.3) IQ domain and CA2+calmodulin complex Deposited 2008-01-14	Different construct Different mutation/modification Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain A 2–149（148 aa）	Not recorded	CA CALCIUM ION × 4 SO4 SULFATE ION × 2	X-RAY DIFFRACTION mmCIF provides none of the parsed conditions	Resolution 2.30 Å R-free 0.262
3BXL Crystal structure of the R-type calcium channeL (CaV2.3) IQ domain and CA2+calmodulin complex Deposited 2008-01-14	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 2 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain A 2–149（148 aa）	Not recorded	CA CALCIUM ION × 8 SO4 SULFATE ION × 4	X-RAY DIFFRACTION mmCIF provides none of the parsed conditions	Resolution 2.30 Å R-free 0.262
3IFK Crystal Structure Of Calcium-Saturated Calmodulin N-terminal Domain Fragment, Residues 1-90 Deposited 2009-07-24	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain A 2–91（90 aa） Fragment：N-TERMINAL DOMAIN FRAGMENT, RESIDUES 1-90	Not recorded	CA CALCIUM ION × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5；277.15 K；20% PEG8000, 5mM calcium-chloride, 100mM citrate, pH 5.0, VAPOR DIFFUSION, HANGING DROP, temperature 277.15K	Resolution 2.03 Å R-free 0.293
3IFK Crystal Structure Of Calcium-Saturated Calmodulin N-terminal Domain Fragment, Residues 1-90 Deposited 2009-07-24	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 2 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain B 2–91（90 aa） Fragment：N-TERMINAL DOMAIN FRAGMENT, RESIDUES 1-90	Not recorded	CA CALCIUM ION × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5；277.15 K；20% PEG8000, 5mM calcium-chloride, 100mM citrate, pH 5.0, VAPOR DIFFUSION, HANGING DROP, temperature 277.15K	Resolution 2.03 Å R-free 0.293
3SJQ Crystal structure of a small conductance potassium channel splice variant complexed with calcium-calmodulin Deposited 2011-06-21	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain A 1–149（149 aa） Chain B 1–149（149 aa）	Not recorded	CA CALCIUM ION × 8 PHU 1-phenylurea × 4 GOL GLYCEROL × 6 SO4 SULFATE ION × 8	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 4.65；277 K；0.75 M Li2SO4, 0.5 M (NH4)2SO4, 0.1 M Sodium citrate pH 4.65 and Silver Bullets 22 reagent 70, VAPOR DIFFUSION, HANGING DROP, temperature 277K	Resolution 1.90 Å R-free 0.201
4EHQ Crystal Structure of Calmodulin Binding Domain of Orai1 in Complex with Ca2+/Calmodulin Displays a Unique Binding Mode Deposited 2012-04-03	Different construct Different mutation/modification Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain A 2–149（148 aa）	Not recorded	CA CALCIUM ION × 4 GBL GAMMA-BUTYROLACTONE × 4	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 6；293 K；0.1 M Bis-Tris pH 6.0, 40% PPG P400, 14% butyrolactone, 1% n-octyl-beta-D-glucopyranoside, VAPOR DIFFUSION, HANGING DROP, temperature 293K	Resolution 1.90 Å R-free 0.216
4G27 Calcium-calmodulin complexed with the calmodulin binding domain from a small conductance potassium channel splice variant and phenylurea Deposited 2012-07-11	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain R 1–149（149 aa）	Not recorded	SO4 SULFATE ION × 6 CA CALCIUM ION × 4 GOL GLYCEROL × 2 PHU 1-phenylurea × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.6；298 K；1.25 M lithium sulfate, 0.5 M ammonium sulfate, 0.1 M sodium citrate, pH 5.6, VAPOR DIFFUSION, HANGING DROP, temperature 298K	Resolution 1.65 Å R-free 0.228
4G28 Calcium-calmodulin complexed with the calmodulin binding domain from a small conductance potassium channel splice variant and EBIO-1 Deposited 2012-07-11	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain R 1–149（149 aa）	Not recorded	SO4 SULFATE ION × 6 CA CALCIUM ION × 4 GOL GLYCEROL × 2 0W8 1-ethyl-1,3-dihydro-2H-benzimidazol-2-one × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.6；298 K；1.25 M lithium sulfate, 0.5 M ammonium sulfate, 0.1 M sodium citrate, pH 5.6, VAPOR DIFFUSION, HANGING DROP, temperature 298K	Resolution 1.63 Å R-free 0.227
4I2Y Crystal Structure of the genetically encoded calcium indicator RGECO1 Deposited 2012-11-23	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Insufficient information Monomer；Protein × 1 PDB declaration: monomeric	Chain A 3–149（147 aa）	Mutation：;Q44N, T46A, T62S, L65M, R68E, V71A, G74S, H77K, A79G, K81R, L89A, V90A, F92V, S94T, I95T, M97K, Y107A, Y109I, S112I, T117V, Y129C, T132A, R174H, T178S, G197A, H198F, N199Q, V201A, V228A, V230I, K240F, K249R, V261I, V262I, T263H, T265N, C274V, F281L, I282R, V284T, S288P, N363D, I366F, K380N, S404G, N414D, E430V ; Non-standard monomer：Yes (specific site not provided by mmCIF)	CA CALCIUM ION × 4	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5；277 K；73mM malonic acid, 10mM ammonium citrate tribasic, 5mM succinic acid, 12mM malic acid, 16mM sodium acetate trihydrate, 20mM sodium formate, 6mM ammonium tartrate dibasic, 12% PEG 3350, pH 5, VAPOR DIFFUSION, HANGING DROP, temperature 277K	Resolution 2.20 Å R-free 0.257
4I2Y Crystal Structure of the genetically encoded calcium indicator RGECO1 Deposited 2012-11-23	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 2 Insufficient information Monomer；Protein × 1 PDB declaration: monomeric	Chain B 3–149（147 aa）	Mutation：;Q44N, T46A, T62S, L65M, R68E, V71A, G74S, H77K, A79G, K81R, L89A, V90A, F92V, S94T, I95T, M97K, Y107A, Y109I, S112I, T117V, Y129C, T132A, R174H, T178S, G197A, H198F, N199Q, V201A, V228A, V230I, K240F, K249R, V261I, V262I, T263H, T265N, C274V, F281L, I282R, V284T, S288P, N363D, I366F, K380N, S404G, N414D, E430V ; Non-standard monomer：Yes (specific site not provided by mmCIF)	CA CALCIUM ION × 4	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5；277 K；73mM malonic acid, 10mM ammonium citrate tribasic, 5mM succinic acid, 12mM malic acid, 16mM sodium acetate trihydrate, 20mM sodium formate, 6mM ammonium tartrate dibasic, 12% PEG 3350, pH 5, VAPOR DIFFUSION, HANGING DROP, temperature 277K	Resolution 2.20 Å R-free 0.257
4IL1 Crystal Structure of the Rat Calcineurin Deposited 2012-12-28	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Insufficient information Monomer；Protein × 1 PDB declaration: monomeric	Chain A 1–149（149 aa）	Not recorded	CA CALCIUM ION × 4	X-RAY DIFFRACTION X-ray crystallization conditions pH 5.6；293 K；PEG 3350, 1-Propanol, Citric acid, pH 5.6, VAPOR DIFFUSION, HANGING DROP, temperature 293K	Resolution 3.00 Å R-free 0.273
4IL1 Crystal Structure of the Rat Calcineurin Deposited 2012-12-28	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 2 Insufficient information Monomer；Protein × 1 PDB declaration: monomeric	Chain B 1–149（149 aa）	Not recorded	CA CALCIUM ION × 4	X-RAY DIFFRACTION X-ray crystallization conditions pH 5.6；293 K；PEG 3350, 1-Propanol, Citric acid, pH 5.6, VAPOR DIFFUSION, HANGING DROP, temperature 293K	Resolution 3.00 Å R-free 0.273
4IL1 Crystal Structure of the Rat Calcineurin Deposited 2012-12-28	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 3 Insufficient information Monomer；Protein × 1 PDB declaration: monomeric	Chain C 1–149（149 aa）	Not recorded	CA CALCIUM ION × 4	X-RAY DIFFRACTION X-ray crystallization conditions pH 5.6；293 K；PEG 3350, 1-Propanol, Citric acid, pH 5.6, VAPOR DIFFUSION, HANGING DROP, temperature 293K	Resolution 3.00 Å R-free 0.273
4IL1 Crystal Structure of the Rat Calcineurin Deposited 2012-12-28	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 4 Insufficient information Monomer；Protein × 1 PDB declaration: monomeric	Chain D 1–149（149 aa）	Not recorded	CA CALCIUM ION × 4	X-RAY DIFFRACTION X-ray crystallization conditions pH 5.6；293 K；PEG 3350, 1-Propanol, Citric acid, pH 5.6, VAPOR DIFFUSION, HANGING DROP, temperature 293K	Resolution 3.00 Å R-free 0.273
4J9Y Calcium-calmodulin complexed with the calmodulin binding domain from a small conductance potassium channel splice variant Deposited 2013-02-17	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain R 1–149（149 aa）	Not recorded	SO4 SULFATE ION × 6 CA CALCIUM ION × 4 GOL GLYCEROL × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.6；298 K；1.25 M lithium sulfate, 0.5 M ammonium sulfate, 0.1 M sodium citrate, pH 5.6, VAPOR DIFFUSION, HANGING DROP, temperature 298.0K	Resolution 1.51 Å R-free 0.216
4J9Z Calcium-calmodulin complexed with the calmodulin binding domain from a small conductance potassium channel splice variant and NS309 Deposited 2013-02-17	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain R 1–149（149 aa）	Not recorded	SO4 SULFATE ION × 8 1KP (3E)-6,7-dichloro-3-(hydroxyimino)-1,3-dihydro-2H-indol-2-one × 2 CA CALCIUM ION × 4 GOL GLYCEROL × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.6；298 K；1.25 M lithium sulfate, 0.5 M ammonium sulfate, 0.1 M sodium citrate, pH 5.6, vapor diffusion, hanging drop, temperature 298.0K	Resolution 1.66 Å R-free 0.221
4OY4 calcium-free CaMPARI v0.2 Deposited 2014-02-10	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Insufficient information Monomer；Protein × 1 PDB declaration: monomeric	Chain A 3–147（145 aa）	Non-standard monomer：Yes (specific site not provided by mmCIF)	SO4 SULFATE ION × 2 GOL GLYCEROL × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 7.5；277.15 K；0.2 M Ammonium sulfate, 0.1 M HEPES pH 7.5, 25% w/v Polyethylene glycol 3,350, 10 mM EGTA	Resolution 2.03 Å R-free 0.235
4QNH Calcium-calmodulin (T79D) complexed with the calmodulin binding domain from a small conductance potassium channel SK2-a Deposited 2014-06-17	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain R 1–149（149 aa）	Mutation：T79D	SO4 SULFATE ION × 2 CA CALCIUM ION × 4	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION；pH 5.6；277.15 K；1.5 M Li2SO4, 0.5 M (NH4)2SO4, 0.1 M sodium citrate, pH 5.6, VAPOR DIFFUSION, temperature 277.15K	Resolution 2.02 Å R-free 0.234
4QNH Calcium-calmodulin (T79D) complexed with the calmodulin binding domain from a small conductance potassium channel SK2-a Deposited 2014-06-17	Different construct Different mutation/modification Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 2 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain R 1–149（149 aa）	Mutation：T79D	SO4 SULFATE ION × 1 CA CALCIUM ION × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION；pH 5.6；277.15 K；1.5 M Li2SO4, 0.5 M (NH4)2SO4, 0.1 M sodium citrate, pH 5.6, VAPOR DIFFUSION, temperature 277.15K	Resolution 2.02 Å R-free 0.234
4RJD TFP bound in alternate orientations to calcium-saturated Calmodulin C-Domains Deposited 2014-10-08	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain A 83–148（66 aa） Fragment：Calmodulin C-Domian, UNP residues 83-148	Not recorded	CA CALCIUM ION × 2 TFP 10-[3-(4-METHYL-PIPERAZIN-1-YL)-PROPYL]-2-TRIFLUOROMETHYL-10H-PHENOTHIAZINE × 2 1PE PENTAETHYLENE GLYCOL × 1 CL CHLORIDE ION × 1 OXL OXALATE ION × 1	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 6.6；288 K；50 mM HEPES, 100 mM KCl, 1mM MgCl2, 5 mM NTA, 50 uM EGTA, with 500 ul of 200 mM potassium thiocyanate, 20% polyethylene glycol 3350, pH 6.6, VAPOR DIFFUSION, HANGING DROP, temperature 288K	Resolution 2.00 Å R-free 0.253
4RJD TFP bound in alternate orientations to calcium-saturated Calmodulin C-Domains Deposited 2014-10-08	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 2 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain B 83–148（66 aa） Fragment：Calmodulin C-Domian, UNP residues 83-148	Not recorded	CA CALCIUM ION × 2 TFP 10-[3-(4-METHYL-PIPERAZIN-1-YL)-PROPYL]-2-TRIFLUOROMETHYL-10H-PHENOTHIAZINE × 2 CL CHLORIDE ION × 1 SCN THIOCYANATE ION × 1	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 6.6；288 K；50 mM HEPES, 100 mM KCl, 1mM MgCl2, 5 mM NTA, 50 uM EGTA, with 500 ul of 200 mM potassium thiocyanate, 20% polyethylene glycol 3350, pH 6.6, VAPOR DIFFUSION, HANGING DROP, temperature 288K	Resolution 2.00 Å R-free 0.253

22 other PDB entries and 44 assemblies. Open the comparison page and filter oligomeric states

View Construct and Data Evidence

UniProt name	CALM_RAT
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–148； UniProt 1–148 Author chain B； PDBConstruct 1–148； UniProt 1–148 Author chain I； PDBConstruct 1–148； UniProt 1–148 Author chain M； PDBConstruct 1–148； UniProt 1–148 Author chain R； PDBConstruct 1–148； UniProt 1–148

Small conductance calcium-activated potassium channel protein 2

Rattus norvegicus

UniProt P70604

State in the Current Structure

Assembly	Oligomeric State	Construct	Mutations and Modifications	Ligands, Ions and Associated Components	Method and Experimental Conditions	Structure Quality
3	Protein heterocomplex Heteromer Protein × 2 PDB declaration: dimeric（2） Consistent with protein copy count	Chain D； UniProt 411–487	Fragment：SK2 gating domain (residues 411-487)	Calmodulin × 1 （P62161）	X-RAY DIFFRACTION X-ray crystallization conditions：VAPOR DIFFUSION, SITTING DROP；pH 6.5；298 K；Citrate, NaCl, Hepes, pH 6.5, VAPOR DIFFUSION, SITTING DROP, temperature 298K	Resolution 3.09 Å R-free 0.308

Other States of the Same Protein in the Database

Other PDB	Difference from Current Entry 1QX7	Assembly / Oligomeric State	Construct	Mutations and Modifications	Ligands, Ions and Non-polymers	Method and Experimental Conditions	Structure Quality
1G4Y 1.60 A CRYSTAL STRUCTURE OF THE GATING DOMAIN FROM SMALL CONDUCTANCE POTASSIUM CHANNEL COMPLEXED WITH CALCIUM-CALMODULIN Deposited 2001-01-07	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain B 369–460（92 aa） Fragment：CALMODULIN-BINDING DOMAIN	Not recorded	SO4 SULFATE ION × 2 CA CALCIUM ION × 4	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.6；298 K；ammonium sulphate, lithium sulphate, citrate, pH 5.6, VAPOR DIFFUSION, HANGING DROP, temperature 298K	Resolution 1.60 Å R-free 0.251
1KKD Solution structure of the calmodulin binding domain (CaMBD) of small conductance Ca2+-activated potassium channels (SK2) Deposited 2001-12-07	Different construct Different oligomeric state Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain A 396–487（92 aa） Fragment：CYTOPLASMIC CALMODULIN BINDING DOMAIN (CAMBD)	Not recorded	No recorded non-water small molecule	SOLUTION NMR NMR measurement conditions pH 3.5；298 K；Ionic strength (raw mmCIF value) 250 mM；Pressure ambient NMR measurement conditions pH 3.5；298 K；Ionic strength (raw mmCIF value) 250 mM；Pressure ambient NMR measurement conditions pH 3.5；298 K；Ionic strength (raw mmCIF value) 250 mM；Pressure ambient NMR measurement conditions pH 3.5；298 K；Ionic strength (raw mmCIF value) 250 mM；Pressure ambient NMR sample composition 0.5 mM U-15N,13C CaMBD (residues 396-487 of rat SK2); 250 mM NaCl, 0.05 % Na-azide \| 90% H2O/10% D2O NMR sample composition 1.2 mM U-15N CaMBD (residues 396-487 of rat SK2); 250 mM NaCl, 0.05 % Na-azide \| 90% H2O/10% D2O NMR sample composition 1 mM CaMBD (residues 396-487 of rat SK2); 250 mM NaCl, 0.05 % Na-azide \| 90% H2O/10% D2O NMR sample composition 1 mM CaMBD (residues 396-487 of rat SK2); 250 mM NaCl, 0.05 % Na-azide \| 100% D2O	Resolution not provided
2PNV Crystal Structure of the leucine zipper domain of small-conductance Ca2+-activated K+ (SKCa) channel from Rattus norvegicus Deposited 2007-04-25	Different construct Different oligomeric state Different experimental conditions Different structure-quality metrics	Assembly 1 Protein homooligomer Homooligomer；Protein × 3 PDB declaration: trimeric	Chain A 488–526（39 aa） Fragment：leucine zipper domain	Not recorded	No recorded non-water small molecule	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.6；298 K；0.1M sodium citrate (pH 5.6), 20-22% (w/v) PEG 8000, VAPOR DIFFUSION, HANGING DROP, temperature 298.0K	Resolution 2.10 Å R-free 0.278
2PNV Crystal Structure of the leucine zipper domain of small-conductance Ca2+-activated K+ (SKCa) channel from Rattus norvegicus Deposited 2007-04-25	Different construct Different oligomeric state Different experimental conditions Different structure-quality metrics	Assembly 2 Protein homooligomer Homooligomer；Protein × 3 PDB declaration: trimeric	Chain B 488–526（39 aa） Fragment：leucine zipper domain	Not recorded	No recorded non-water small molecule	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.6；298 K；0.1M sodium citrate (pH 5.6), 20-22% (w/v) PEG 8000, VAPOR DIFFUSION, HANGING DROP, temperature 298.0K	Resolution 2.10 Å R-free 0.278
2PNV Crystal Structure of the leucine zipper domain of small-conductance Ca2+-activated K+ (SKCa) channel from Rattus norvegicus Deposited 2007-04-25	Different construct Different mutation/modification Different oligomeric state Different experimental conditions Different structure-quality metrics	Assembly 3 Protein homooligomer Homooligomer；Protein × 6 PDB declaration: hexameric	Chain A 488–526（39 aa） Fragment：leucine zipper domain Chain B 488–526（39 aa） Fragment：leucine zipper domain	Not recorded	No recorded non-water small molecule	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.6；298 K；0.1M sodium citrate (pH 5.6), 20-22% (w/v) PEG 8000, VAPOR DIFFUSION, HANGING DROP, temperature 298.0K	Resolution 2.10 Å R-free 0.278
3SJQ Crystal structure of a small conductance potassium channel splice variant complexed with calcium-calmodulin Deposited 2011-06-21	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain C 412–487（76 aa） Fragment：Calmodulin binding domain, UNP residues 412-487 Chain D 412–487（76 aa） Fragment：Calmodulin binding domain, UNP residues 412-487	Not recorded	CA CALCIUM ION × 8 PHU 1-phenylurea × 4 GOL GLYCEROL × 6 SO4 SULFATE ION × 8	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 4.65；277 K；0.75 M Li2SO4, 0.5 M (NH4)2SO4, 0.1 M Sodium citrate pH 4.65 and Silver Bullets 22 reagent 70, VAPOR DIFFUSION, HANGING DROP, temperature 277K	Resolution 1.90 Å R-free 0.201
4G27 Calcium-calmodulin complexed with the calmodulin binding domain from a small conductance potassium channel splice variant and phenylurea Deposited 2012-07-11	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain B 396–487（92 aa） Fragment：calmodulin binding domain (UNP residues 396-487)	Not recorded	SO4 SULFATE ION × 6 CA CALCIUM ION × 4 GOL GLYCEROL × 2 PHU 1-phenylurea × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.6；298 K；1.25 M lithium sulfate, 0.5 M ammonium sulfate, 0.1 M sodium citrate, pH 5.6, VAPOR DIFFUSION, HANGING DROP, temperature 298K	Resolution 1.65 Å R-free 0.228
4G28 Calcium-calmodulin complexed with the calmodulin binding domain from a small conductance potassium channel splice variant and EBIO-1 Deposited 2012-07-11	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain B 396–487（92 aa） Fragment：calmodulin binding domain (UNP residues 396-487)	Not recorded	SO4 SULFATE ION × 6 CA CALCIUM ION × 4 GOL GLYCEROL × 2 0W8 1-ethyl-1,3-dihydro-2H-benzimidazol-2-one × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.6；298 K；1.25 M lithium sulfate, 0.5 M ammonium sulfate, 0.1 M sodium citrate, pH 5.6, VAPOR DIFFUSION, HANGING DROP, temperature 298K	Resolution 1.63 Å R-free 0.227
4J9Y Calcium-calmodulin complexed with the calmodulin binding domain from a small conductance potassium channel splice variant Deposited 2013-02-17	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain B 396–487（92 aa） Fragment：Calmodulin Binding Domain (UNP residues 396-487)	Not recorded	SO4 SULFATE ION × 6 CA CALCIUM ION × 4 GOL GLYCEROL × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.6；298 K；1.25 M lithium sulfate, 0.5 M ammonium sulfate, 0.1 M sodium citrate, pH 5.6, VAPOR DIFFUSION, HANGING DROP, temperature 298.0K	Resolution 1.51 Å R-free 0.216
4J9Z Calcium-calmodulin complexed with the calmodulin binding domain from a small conductance potassium channel splice variant and NS309 Deposited 2013-02-17	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain B 396–487（92 aa） Fragment：Calmodulin Binding Domain (UNP residues 396-487)	Not recorded	SO4 SULFATE ION × 8 1KP (3E)-6,7-dichloro-3-(hydroxyimino)-1,3-dihydro-2H-indol-2-one × 2 CA CALCIUM ION × 4 GOL GLYCEROL × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 5.6；298 K；1.25 M lithium sulfate, 0.5 M ammonium sulfate, 0.1 M sodium citrate, pH 5.6, vapor diffusion, hanging drop, temperature 298.0K	Resolution 1.66 Å R-free 0.221
4QNH Calcium-calmodulin (T79D) complexed with the calmodulin binding domain from a small conductance potassium channel SK2-a Deposited 2014-06-17	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain B 396–487（92 aa） Fragment：Calmodulin binding domain (UNP residues 396-487)	Not recorded	SO4 SULFATE ION × 2 CA CALCIUM ION × 4	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION；pH 5.6；277.15 K；1.5 M Li2SO4, 0.5 M (NH4)2SO4, 0.1 M sodium citrate, pH 5.6, VAPOR DIFFUSION, temperature 277.15K	Resolution 2.02 Å R-free 0.234
4QNH Calcium-calmodulin (T79D) complexed with the calmodulin binding domain from a small conductance potassium channel SK2-a Deposited 2014-06-17	Different construct Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 2 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain B 396–487（92 aa） Fragment：Calmodulin binding domain (UNP residues 396-487)	Not recorded	SO4 SULFATE ION × 1 CA CALCIUM ION × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION；pH 5.6；277.15 K；1.5 M Li2SO4, 0.5 M (NH4)2SO4, 0.1 M sodium citrate, pH 5.6, VAPOR DIFFUSION, temperature 277.15K	Resolution 2.02 Å R-free 0.234
6CZQ A V-to-F substitution in SK2 channels causes Ca2+ hypersensitivity and improves locomotion in a C. elegans ALS model Deposited 2018-04-09	Different construct Different mutation/modification Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain B 395–487（93 aa） Fragment：residues 395-487	Mutation：A395G, V407F	SO4 SULFATE ION × 3 CA CALCIUM ION × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, SITTING DROP；pH 5.6；293.15 K；0.1 M Sodium citrate tribasic dihydrate 0.5 M Ammonium sulfate 1.5 M Lithium sulfate monohydrate	Resolution 2.20 Å R-free 0.249
8V2G Cryo-EM structure of the KCa2.2 channel in apo state Deposited 2023-11-22	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric	Chain A 118–478（361 aa） Fragment：UNP residues 118-478 Chain B 118–478（361 aa） Fragment：UNP residues 118-478 Chain C 118–478（361 aa） Fragment：UNP residues 118-478 Chain D 118–478（361 aa） Fragment：UNP residues 118-478	Not recorded	K POTASSIUM ION × 4 CA CALCIUM ION × 8	ELECTRON MICROSCOPY cryo-EM buffer pH 8 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.18 Å
8V2H Cryo-EM structure of the KCa2.2 channel bound to inhibitor AP14145. Deposited 2023-11-22	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric	Chain A 118–478（361 aa） Fragment：UNP residues 118-478 Chain B 118–478（361 aa） Fragment：UNP residues 118-478 Chain C 118–478（361 aa） Fragment：UNP residues 118-478 Chain D 118–478（361 aa） Fragment：UNP residues 118-478	Not recorded	K POTASSIUM ION × 4 CA CALCIUM ION × 8	ELECTRON MICROSCOPY cryo-EM buffer pH 8 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.10 Å
8V3G Cryo-EM structure of the KCa2.2 channel with inhibitor UCL 1684. Deposited 2023-11-27	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric	Chain A 118–478（361 aa） Fragment：UNP residues 118-478 Chain B 118–478（361 aa） Fragment：UNP residues 118-478 Chain C 118–478（361 aa） Fragment：UNP residues 118-478 Chain D 118–478（361 aa） Fragment：UNP residues 118-478	Not recorded	K POTASSIUM ION × 4 Y7Z UCL1684 × 1 CA CALCIUM ION × 8	ELECTRON MICROSCOPY cryo-EM buffer pH 8 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.10 Å
9EIO Cryo-EM structure of the mutant KCa2.2_F244S channel Deposited 2024-11-26	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric	Chain A 118–478（361 aa） Fragment：UNP residues 118-478 Chain B 118–478（361 aa） Fragment：UNP residues 118-478 Chain C 118–478（361 aa） Fragment：UNP residues 118-478 Chain D 118–478（361 aa） Fragment：UNP residues 118-478	Not recorded	K POTASSIUM ION × 4 CA CALCIUM ION × 8	ELECTRON MICROSCOPY cryo-EM buffer pH 8 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.62 Å
9O7S Cryo-EM structure of KCa2.2/calmodulin channel in complex with NS309 Deposited 2025-04-15	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric	Chain A 118–478（361 aa） Fragment：UNP residues 118-478 Chain B 118–478（361 aa） Fragment：UNP residues 118-478 Chain C 118–478（361 aa） Fragment：UNP residues 118-478 Chain D 118–478（361 aa） Fragment：UNP residues 118-478	Not recorded	K POTASSIUM ION × 3 1KP (3E)-6,7-dichloro-3-(hydroxyimino)-1,3-dihydro-2H-indol-2-one × 4 CA CALCIUM ION × 8	ELECTRON MICROSCOPY cryo-EM buffer pH 8 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 2.71 Å
9O85 Cryo-EM structure of KCa2.2_I/calmodulin channel in complex with rimtuzalcap Deposited 2025-04-15	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric	Chain A 121–500（380 aa） Fragment：UNP residues 121-500 Chain B 121–500（380 aa） Fragment：UNP residues 121-500 Chain C 121–500（380 aa） Fragment：UNP residues 121-500 Chain D 121–500（380 aa） Fragment：UNP residues 121-500	Not recorded	K POTASSIUM ION × 3 A1B92 Rimtuzalcap × 4 CA CALCIUM ION × 8	ELECTRON MICROSCOPY cryo-EM buffer pH 8 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.13 Å
9O93 Cryo-EM structure of KCa2.2_II/calmodulin channel in complex with rimtuzalcap Deposited 2025-04-17	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric	Chain A 121–500（380 aa） Chain B 121–500（380 aa） Chain C 121–500（380 aa） Chain D 121–500（380 aa）	Not recorded	K POTASSIUM ION × 2 A1B92 Rimtuzalcap × 4	ELECTRON MICROSCOPY cryo-EM buffer pH 8 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 2.96 Å

17 other PDB entries and 20 assemblies. Open the comparison page and filter oligomeric states

View Construct and Data Evidence

UniProt name	KCNN2_RAT
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain D； PDBConstruct 1–77； UniProt 411–487

The page prioritizes protein identity, the current assembly, associated components, oligomeric state and cross-PDB links. Chain mapping and sequence ranges are retained as data evidence. Internal IDs, import timestamps and assembly operation expressions are maintenance fields and are not shown here.

SAXS scattering curve SAXS Profile

P(r) Distance Distribution P(r) Distribution

Download Download SAXS (.dat) P(r) (.pr.out) CIF

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2. Structure Basics 2. Structure Basics

Entry ID entry_id	1qx7
Deposition date deposition_date	2003-09-04
Structure title title	Crystal structure of apoCaM bound to the gating domain of small conductance Ca2+-activated potassium channel
Keywords keywords	;apoCalmodulin, SK channel, small conductance Ca2+ activated K+ channel, CaMBD, gating domain, Ca2+-activated gating, functioanl bipartism, SIGNALING PROTEIN ;; SIGNALING PROTEIN
Experimental Method method	X-RAY DIFFRACTION

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3. SAXS Parameters (CRYSOL theoretical calculation) 3. SAXS Parameters (CRYSOL)

Radius of gyration Rg (Guinier) rg_guinier	33.87 Å
Radius of gyration Rg (electron density) rg_electron	33.83 Å
Forward intensity I(0) i0	123743000.00
Molecular weight molecular_weight	81035.0 kDa
Excluded volume excluded_volume	97257 Å³
Envelope volume envelope_volume	131510 Å³
Hydration-shell volume shell_volume	35045 Å³
Envelope diameter envelope_diameter	126.3 Å
Shell Rg shell_rg	37.29 Å
Envelope Rg envelope_rg	33.53 Å
Shape Rg shape_rg	33.85 Å
Total Rg total_rg	34.04 Å
Total atoms total_atoms	5523
Residues n_residues	654
Spherical-harmonic order n_harmonics	20
q range q_range	— – 0.5000 Å⁻¹
Data points n_points	101
Shell type shell_type	directional
Solvent electron density solvent_density	0.3340 e/Å³
Shell contrast contrast_shell	0.0300 e/Å³
CRYSOL version crysol_version	4.1.3

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4. P(r) Distance Distribution (GNOM inversion) 4. P(r) Analysis (GNOM)

Maximum dimension Dmax dmax	118.2 Å
Rg (real space) rg_real	34.12 Å
Rg uncertainty (real space) rg_real_error	1.36 Å
I(0) (real space) i0_real	1.2370e+08
I(0) uncertainty (real space) i0_real_error	2.3940e+06
Rg (reciprocal space) rg_reciprocal	33.97 Å
I(0) (reciprocal space) i0_reciprocal	123700000.0000
Solution quality estimate total_estimate	0.8356
Solution quality rating solution_quality	GOOD a GOOD solution
P(r) peaks n_peaks	2
Primary peak position r_peak_primary	37.7 Å
Skewness Skewness skewness	0.577
Kurtosis Kurtosis kurtosis	-0.062
Angular range angular_range	— – 0.2350 Å⁻¹
Current regularization parameter α current_alpha	0.0000
Highest regularization parameter α highest_alpha	11980000.0000
Real-space data points n_real_points	48
GNOM version gnom_version	4.1.3
Quality Criteria quality_criteria	AN1: 0.000; Oscil: 0.774; Stabil: 1.000; Sysdev: 1.000; Positv: 1.000; Valcen: 0.770; Smooth: 0.766

▶

5. Crystallography and Experiment 5. Crystallography & Experiment

▶

6. Entities and Polymers Entities & Polymers (2)

Entity 1 Entity 1 polymer

Description description	Calmodulin
Molecular weight formula_weight	17143.4 kDa
Source method src_method	man
Copy count entity_count	5

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	I,R,A,B,M
Atom count atom_count	5523

ADQLTEEQIAEFKEAFSLFDKDGDGTITTKELGTVMRSLGQNPTEAELQDMINEVDADGNGTIDFPEFLTMMARKMKDTDSEEEIREAFRVFDKDGNGYISAAELRHVMTNLGEKLTDEEVDEMIREADIDGDGQVNYEEFVQMMTAK

来源 Source

来源生物 organism	Rattus norvegicus
通用名 common_name	Norway rat
NCBI Class编号 ncbi_taxonomy_id	10116
宿主生物 host_organism	Escherichia coli BL21(DE3)

Entity 2 Entity 2 polymer

Description description	Small conductance calcium-activated potassium channel protein 2
Molecular weight formula_weight	10217.0 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	D

MMDTQLTKRVKNAAANVLRETWLIYKNTKLVKKIDHAKVRKHQRKFLQAIHQLRSVKMEQRKLNDQANTLVDLAKTQLEHHHHHH

来源 Source

来源生物 organism	Rattus norvegicus
通用名 common_name	Norway rat
NCBI Class编号 ncbi_taxonomy_id	10116
宿主生物 host_organism	Escherichia coli BL21(DE3)

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7. Fold Classification (SCOP + CATH) 13 domains

SCOP 2.08 (5 domains)

Domain ID domain_id	d1qx7a_
Class class	a — All alpha proteins
Fold Fold fold	a.39 — EF Hand-like
Superfamily Superfamily superfamily	a.39.1 — EF-hand
Family Family family	a.39.1.5 — Calmodulin-like

Domain ID domain_id	d1qx7b_
Class class	a — All alpha proteins
Fold Fold fold	a.39 — EF Hand-like
Superfamily Superfamily superfamily	a.39.1 — EF-hand
Family Family family	a.39.1.5 — Calmodulin-like

Domain ID domain_id	d1qx7i_
Class class	a — All alpha proteins
Fold Fold fold	a.39 — EF Hand-like
Superfamily Superfamily superfamily	a.39.1 — EF-hand
Family Family family	a.39.1.5 — Calmodulin-like

Domain ID domain_id	d1qx7m_
Class class	a — All alpha proteins
Fold Fold fold	a.39 — EF Hand-like
Superfamily Superfamily superfamily	a.39.1 — EF-hand
Family Family family	a.39.1.5 — Calmodulin-like

Domain ID domain_id	d1qx7r_
Class class	a — All alpha proteins
Fold Fold fold	a.39 — EF Hand-like
Superfamily Superfamily superfamily	a.39.1 — EF-hand
Family Family family	a.39.1.5 — Calmodulin-like

CATH v4.4 (8 domains)

Domain ID domain_id	1qx7A01
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	238 — Recoverin; domain 1
Homologous superfamily homologous superfamily	10 — EF-hand

Domain ID domain_id	1qx7A02
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	238 — Recoverin; domain 1
Homologous superfamily homologous superfamily	10 — EF-hand

Domain ID domain_id	1qx7B00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	238 — Recoverin; domain 1
Homologous superfamily homologous superfamily	10 — EF-hand

Domain ID domain_id	1qx7I01
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	238 — Recoverin; domain 1
Homologous superfamily homologous superfamily	10 — EF-hand

Domain ID domain_id	1qx7I02
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	238 — Recoverin; domain 1
Homologous superfamily homologous superfamily	10 — EF-hand

Domain ID domain_id	1qx7M01
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	238 — Recoverin; domain 1
Homologous superfamily homologous superfamily	10 — EF-hand

Domain ID domain_id	1qx7R01
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	238 — Recoverin; domain 1
Homologous superfamily homologous superfamily	10 — EF-hand

Domain ID domain_id	1qx7R02
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	238 — Recoverin; domain 1
Homologous superfamily homologous superfamily	10 — EF-hand

▶

8. Citations (1)

▶

Unit-cell length a length_a	79.930 Å
Unit-cell length b length_b	79.930 Å
Unit-cell length c length_c	220.800 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	90.00 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	40

Space group space_group	P 41 21 2
Space-group number int_tables_number	92
Crystal system crystal_system	—

Resolution resolution	3.090 Å
Low-resolution limit resolution_low	75.160 Å
R factor r_factor	0.2860
R_work r_work	0.2860
R_free r_free	0.3080

fit	/app/data/saxs_computation/qx/1qx7/1qx7.fit
pddf	/app/data/pr_computation/qx/1qx7/1qx7.pr.out
profile	/app/data/saxs_computation/qx/1qx7/1qx7.dat

Crystal structure of apoCaM bound to the gating domain of small conductance Ca2+-activated potassium channel

1. Protein Identity and Related Structures Protein Identity & Related Structures

Calmodulin

State in the Current Structure

Other States of the Same Protein in the Database

Small conductance calcium-activated potassium channel protein 2

State in the Current Structure

Other States of the Same Protein in the Database

SAXS scattering curve SAXS Profile

P(r) Distance Distribution P(r) Distribution

2. Structure Basics 2. Structure Basics

3. SAXS Parameters (CRYSOL theoretical calculation) 3. SAXS Parameters (CRYSOL)

4. P(r) Distance Distribution (GNOM inversion) 4. P(r) Analysis (GNOM)

5. Crystallography and Experiment 5. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

Diffraction experiment Diffraction

6. Entities and Polymers Entities & Polymers (2)

Entity 1 Entity 1 polymer

Polymer Polymer

来源 Source

Entity 2 Entity 2 polymer

Polymer Polymer

来源 Source

7. Fold Classification (SCOP + CATH) 13 domains

SCOP 2.08 (5 domains)

CATH v4.4 (8 domains)

8. Citations (1)

9. Files and Curves (10)

Files (7)

Curves (3)