9EIO: Mutant KCa2.2_F244S channel
Cryo-EM structure of the mutant KCa2.2_F244S channel. Determined by electron microscopy at 3.62 Å resolution. Released 23 Apr 2025.
- Method
- Electron microscopy
- Resolution
- 3.62 Å
- Organism
- Rattus norvegicus
- Chains
- 8
- Atoms
- 14,654
- Mol. weight
- 229.35 kDa
- Ligands
- CA
- Released
- 23 Apr 2025
Explore 9EIO in 3D
Show helices and sheets
RCSB PDB
PDBe
Secondary structure: helices and β-sheets
9EIO contains 124 α-helices and 4 β-strands across 8 chains. Residue ranges use author residue numbering, as in the PDB file, from PDBe. To see them in 3D, choose the Cartoon representation with Secondary structure coloring: helices, sheets and coils get different colors.
Chain A: 22 helices, 0 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 119-144 | 26 | |
| α-helix | 146-157 | 12 | |
| α-helix | 167-201 | 35 | |
| α-helix | 212-225 | 14 | |
| α-helix | 255-258 | 4 | |
| α-helix | 261-263 | 3 | |
| α-helix | 266-268 | 3 | |
| α-helix | 269-274 | 6 | |
| α-helix | 285-287 | 3 | |
| α-helix | 301-306 | 6 | |
| α-helix | 313-318 | 6 | |
| α-helix | 323-326 | 4 | |
| α-helix | 328-333 | 6 | |
| α-helix | 346-349 | 4 | |
| α-helix | 352-357 | 6 | |
| α-helix | 370-381 | 12 | |
| α-helix | 387-395 | 9 | |
| α-helix | 396-398 | 3 | |
| α-helix | 405-414 | 10 | |
| α-helix | 416-418 | 3 | |
| α-helix | 420-438 | 19 | |
| α-helix | 450-475 | 26 | |
Chain B: 21 helices, 0 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 124-133 | 10 | |
| α-helix | 138-157 | 20 | |
| α-helix | 167-200 | 34 | |
| α-helix | 212-225 | 14 | |
| α-helix | 255-258 | 4 | |
| α-helix | 261-263 | 3 | |
| α-helix | 266-268 | 3 | |
| α-helix | 269-274 | 6 | |
| α-helix | 285-290 | 6 | |
| α-helix | 301-309 | 9 | |
| α-helix | 313-320 | 8 | |
| α-helix | 323-326 | 4 | |
| α-helix | 328-334 | 7 | |
| α-helix | 349-357 | 9 | |
| α-helix | 370-379 | 10 | |
| α-helix | 389-396 | 8 | |
| α-helix | 405-414 | 10 | |
| α-helix | 416-418 | 3 | |
| α-helix | 420-438 | 19 | |
| α-helix | 446-473 | 28 | |
| α-helix | 474-476 | 3 | |
Chain C: 24 helices, 0 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 119-133 | 15 | |
| α-helix | 135-144 | 10 | |
| α-helix | 146-157 | 12 | |
| α-helix | 167-200 | 34 | |
| α-helix | 212-225 | 14 | |
| α-helix | 255-258 | 4 | |
| α-helix | 261-263 | 3 | |
| α-helix | 266-268 | 3 | |
| α-helix | 269-274 | 6 | |
| α-helix | 285-288 | 4 | |
| α-helix | 290-293 | 4 | |
| α-helix | 301-309 | 9 | |
| α-helix | 313-320 | 8 | |
| α-helix | 323-326 | 4 | |
| α-helix | 328-333 | 6 | |
| α-helix | 352-357 | 6 | |
| α-helix | 372-381 | 10 | |
| α-helix | 390-396 | 7 | |
| α-helix | 403-414 | 12 | |
| α-helix | 416-418 | 3 | |
| α-helix | 420-438 | 19 | |
| α-helix | 446-448 | 3 | |
| α-helix | 450-456 | 7 | |
| α-helix | 458-475 | 18 | |
Chain D: 21 helices, 0 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 119-133 | 15 | |
| α-helix | 135-157 | 23 | |
| α-helix | 167-200 | 34 | |
| α-helix | 212-225 | 14 | |
| α-helix | 255-258 | 4 | |
| α-helix | 261-263 | 3 | |
| α-helix | 266-268 | 3 | |
| α-helix | 269-274 | 6 | |
| α-helix | 279-282 | 4 | |
| α-helix | 301-309 | 9 | |
| α-helix | 313-316 | 4 | |
| α-helix | 323-326 | 4 | |
| α-helix | 328-334 | 7 | |
| α-helix | 346-349 | 4 | |
| α-helix | 352-357 | 6 | |
| α-helix | 372-381 | 10 | |
| α-helix | 387-397 | 11 | |
| α-helix | 402-414 | 13 | |
| α-helix | 416-418 | 3 | |
| α-helix | 420-438 | 19 | |
| α-helix | 446-476 | 31 | |
Chain E: 10 helices, 2 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 6-8 | 3 | |
| α-helix | 10-19 | 10 | |
| β-strand | 27 | 1 | 1 |
| α-helix | 29-39 | 11 | |
| α-helix | 45-55 | 11 | |
| β-strand | 63 | 1 | 1 |
| α-helix | 65-72 | 8 | |
| α-helix | 83-87 | 5 | |
| α-helix | 90-92 | 3 | |
| α-helix | 102-110 | 9 | |
| α-helix | 118-127 | 10 | |
| α-helix | 138-142 | 5 | |
Chain F: 11 helices, 0 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 6-8 | 3 | |
| α-helix | 10-18 | 9 | |
| α-helix | 29-39 | 11 | |
| α-helix | 45-53 | 9 | |
| α-helix | 65-72 | 8 | |
| α-helix | 84-87 | 4 | |
| α-helix | 90-92 | 3 | |
| α-helix | 102-110 | 9 | |
| α-helix | 118-121 | 4 | |
| α-helix | 122-124 | 3 | |
| α-helix | 138-143 | 6 | |
Chain G: 7 helices, 0 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 11-19 | 9 | |
| α-helix | 29-39 | 11 | |
| α-helix | 45-52 | 8 | |
| α-helix | 65-72 | 8 | |
| α-helix | 84-91 | 8 | |
| α-helix | 105-111 | 7 | |
| α-helix | 120-127 | 8 | |
Chain H: 8 helices, 2 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 10-18 | 9 | |
| α-helix | 29-35 | 7 | |
| α-helix | 45-52 | 8 | |
| α-helix | 65-72 | 8 | |
| α-helix | 81-92 | 12 | |
| β-strand | 100 | 1 | 2 |
| α-helix | 105-111 | 7 | |
| α-helix | 120-126 | 7 | |
| α-helix | 129-131 | 3 | |
| β-strand | 136 | 1 | 2 |
Molecules and chains
| Molecule | Chains | Type | Length | Organism | UniProt |
|---|
| Small conductance calcium-activated potassium channel protein 2 | A, B, C, D | protein | 361 | Rattus norvegicus | P70604 (AlphaFold model) |
| Calmodulin-1 | E, F, G, H | protein | 142 | Rattus norvegicus | P0DP29 (AlphaFold model) |
Sequence of entity 1 (A, B, C, D), FASTA
>9EIO_1 Small conductance calcium-activated potassium channel protein 2 (chains A, B, C, D)
IGYKLGHRRALFEKRKRLSDYALIFGMFGIVVMVIETELSWGAYDKASLYSLALKCLISL
STIILLGLIIVYHAREIQLFMVDNGADDWRIAMTYERIFFICLEILVCAIHPIPGNYTFT
WTARLAFSYAPSTTTADVDIILSIPMFLRLYLIARVMLLHSKLFTDASSRSIGALNKINF
NTRFVMKTLMTICPGTVLLVFSISLWIIAAWTVRACERYHDQQDVTSNFLGAMWLISITF
LSIGYGDMVPNTYCGKGVCLLTGIMGAGCTALVVAVVARKLELTKAEKHVHNFMMDTQLT
KRVKNAAANVLRETWLIYKNTKLVKKIDHAKVRKHQRKFLQAIHQLRSVKMEQRKLNDQA
N
Sequence of entity 2 (E, F, G, H), FASTA
>9EIO_2 Calmodulin-1 (chains E, F, G, H)
QLTEEQIAEFKEAFSLFDKDGDGTITTKELGTVMRSLGQNPTEAELQDMINEVDADGNGT
IDFPEFLTMMARKMKDTDSEEEIREAFRVFDKDGNGYISAAELRHVMTNLGEKLTDEEVD
EMIREADIDGDGQVNYEEFVQM
Ligands and cofactors
| ID | Name | Formula | Copies |
|---|
| CA | Calcium ion | Ca | 8 |
Water and common crystallization additives (K) are not listed.
Primary citation
Cryo-EM structures of the small-conductance Ca 2+ -activated K Ca 2.2 channel. Nam, Y.W., Im, D., Garcia, A.S.C. et al. Nat Commun (2025) 16:3690-3690. DOI 10.1038/s41467-025-59061-1 · PubMed
Other PDB entries of the same protein (UniProt P70604 (AlphaFold model), which also has an AlphaFold model), best resolution first:
- 4J9Y 1.51 Å, Calcium-calmodulin complexed with the calmodulin binding domain from a small conductance…
- 1G4Y 1.6 Å, 1.60 a crystal structure of the gating domain from small conductance potassium channel…
- 4G28 1.63 Å, Calcium-calmodulin complexed with the calmodulin binding domain from a small conductance…
- 4G27 1.65 Å, Calcium-calmodulin complexed with the calmodulin binding domain from a small conductance…
- 4J9Z 1.66 Å, Calcium-calmodulin complexed with the calmodulin binding domain from a small conductance…
- 3SJQ 1.9 Å, Crystal structure of a small conductance potassium channel splice variant complexed with…
- 4QNH 2.02 Å, Calcium-calmodulin (T79D) complexed with the calmodulin binding domain from a small…
- 2PNV 2.1 Å, Crystal Structure of the leucine zipper domain of small-conductance Ca2+-activated K+…
- 6CZQ 2.2 Å, A V-to-F substitution in SK2 channels causes Ca2+ hypersensitivity and improves…
- 9O7S 2.71 Å, Cryo-EM structure of KCa2.2/calmodulin channel in complex with NS309
- 9O93 2.96 Å, Cryo-EM structure of KCa2.2_II/calmodulin channel in complex with rimtuzalcap
- 1QX7 3.09 Å, Crystal structure of apoCaM bound to the gating domain of small conductance…
Browse structure collections
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