Small conductance calcium-activated potassium channel protein 2
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 heterocomplex Heteromer Protein × 2 PDB declaration: dimeric(2) Consistent with protein copy count | Chain B; UniProt 395–487 | Fragment:residues 395-487 Mutation:A395G, V407F | Calmodulin-1 × 1 (P0DP29) 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 |
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 6CZQ | 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 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 mutation/modification Different oligomeric state Different ligand/ion 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 |
| 1QX7 Crystal structure of apoCaM bound to the gating domain of small conductance Ca2+-activated potassium channel Deposited 2003-09-04 | Different construct Different mutation/modification Different ligand/ion Different experimental conditions Different structure-quality metrics | Assembly 3 Protein heterocomplex Heteromer;Protein × 2 PDB declaration: dimeric |
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 | Different construct Different mutation/modification Different oligomeric state Different ligand/ion 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 mutation/modification Different oligomeric state Different ligand/ion 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 ligand/ion 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 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 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 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 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 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 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 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 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 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 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 mutation/modification 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 |
| 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 | 1 |
| Chains and sequence ranges | Author chain B; PDBConstruct 1–93; UniProt 395–487 |