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Protein Structures and Oligomeric States

Enter a protein name, UniProt accession or PDB ID. Name searches ask you to confirm the protein identity before related structures are queried.

Current Protein Identity：P70604 New Search
18PDB entries
21Biological assembly
44chain/assembly records
Main Difference Dimensions in This Set
Different construct Different mutation/modification Different assembly state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics

Difference tags compare only the current result set; every original PDB and assembly record remains separate.

Related-Structure Differences

Each row represents one biological assembly in one PDB entry; multiple monomers of the same protein are listed separately.

PDB Entry Assembly / Oligomeric State Construct Mutations and Modifications Ligands, Ions and Non-polymers Experimental Method 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 Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric（4） Consistent with protein count
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 Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric（1） Consistent with protein count
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
1QX7 Crystal structure of apoCaM bound to the gating domain of small conductance Ca2+-activated potassium channel Deposited 2003-09-04 Assembly 3 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric（2） Consistent with protein count
Chain D 411–487（77 aa） Fragment：SK2 gating domain (residues 411-487)
Not recorded No recorded non-water small molecule 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
2PNV Crystal Structure of the leucine zipper domain of small-conductance Ca2+-activated K+ (SKCa) channel from Rattus norvegicus Deposited 2007-04-25 Assembly 1 Protein homooligomer Homooligomer；Protein × 3 PDB declaration: trimeric（3） Consistent with protein count
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 Assembly 2 Protein homooligomer Homooligomer；Protein × 3 PDB declaration: trimeric（3） Consistent with protein count
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 Assembly 3 Protein homooligomer Homooligomer；Protein × 6 PDB declaration: hexameric（6） Consistent with protein count
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 Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric（4） Consistent with protein count
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 Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric（4） Consistent with protein count
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 Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric（4） Consistent with protein count
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 Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric（4） Consistent with protein count
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 Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric（4） Consistent with protein count
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 Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric（4） Consistent with protein count
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 Assembly 2 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric（2） Consistent with protein count
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 Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric（2） Consistent with protein count
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 Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric（8） Consistent with protein count
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 Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric（8） Consistent with protein count
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 Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric（8） Consistent with protein count
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 Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric（8） Consistent with protein count
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 Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric（8） Consistent with protein count
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 Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric（8） Consistent with protein count
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 Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric（8） Consistent with protein count
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

This page presents structural evidence recorded in PDB/mmCIF.“No recorded non-water small molecule” does not prove that the experimental sample was ligand-free; experimental conditions belong to the PDB experiment, while ligands and copy counts are shown for each biological assembly.