8SIK: KCNQ1 with voltage sensor in the up conformation
KCNQ1 with voltage sensor in the up conformation. Determined by electron microscopy at 2.9 Å resolution. Released 31 May 2023.
- Method
- Electron microscopy
- Resolution
- 2.9 Å
- Organism
- Homo sapiens
- Chains
- 8
- Atoms
- 15,832
- Mol. weight
- 320.77 kDa
- Ligands
- CA
- Released
- 31 May 2023
Explore 8SIK in 3D
Show helices and sheets
RCSB PDB
PDBe
Secondary structure: helices and β-sheets
8SIK contains 112 α-helices and 16 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: 19 helices, 0 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 106-114 | 9 | |
| α-helix | 121-143 | 23 | |
| α-helix | 149-177 | 29 | |
| α-helix | 178-180 | 3 | |
| α-helix | 186-195 | 10 | |
| α-helix | 197-215 | 19 | |
| α-helix | 224-236 | 13 | |
| α-helix | 237-241 | 5 | |
| α-helix | 246-257 | 12 | |
| α-helix | 259-283 | 25 | |
| α-helix | 299-310 | 12 | |
| α-helix | 323-357 | 35 | |
| α-helix | 358-360 | 3 | |
| α-helix | 361-363 | 3 | |
| α-helix | 364-367 | 4 | |
| α-helix | 368-383 | 16 | |
| α-helix | 390-395 | 6 | |
| α-helix | 510-532 | 23 | |
| α-helix | 538-567 | 30 | |
Chains B, D and H: 8 helices, 4 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 7-21 | 15 | |
| β-strand | 28 | 1 | 1 |
| α-helix | 30-40 | 11 | |
| α-helix | 46-56 | 11 | |
| β-strand | 64 | 1 | 1 |
| α-helix | 66-73 | 8 | |
| α-helix | 80-91 | 12 | |
| β-strand | 100-102 | 3 | 2 |
| α-helix | 103-112 | 10 | |
| α-helix | 119-128 | 10 | |
| β-strand | 136-138 | 3 | 2 |
| α-helix | 139-148 | 10 | |
Chain C: 20 helices, 0 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 106-114 | 9 | |
| α-helix | 121-144 | 24 | |
| α-helix | 149-177 | 29 | |
| α-helix | 178-180 | 3 | |
| α-helix | 186-194 | 9 | |
| α-helix | 197-215 | 19 | |
| α-helix | 224-236 | 13 | |
| α-helix | 237-241 | 5 | |
| α-helix | 246-257 | 12 | |
| α-helix | 259-283 | 25 | |
| α-helix | 299-310 | 12 | |
| α-helix | 323-357 | 35 | |
| α-helix | 358-360 | 3 | |
| α-helix | 361-363 | 3 | |
| α-helix | 364-367 | 4 | |
| α-helix | 368-383 | 16 | |
| α-helix | 390-395 | 6 | |
| α-helix | 510-532 | 23 | |
| α-helix | 535-536 | 2 | |
| α-helix | 538-567 | 30 | |
Chain E: 21 helices, 0 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 106-114 | 9 | |
| α-helix | 121-144 | 24 | |
| α-helix | 149-177 | 29 | |
| α-helix | 178-180 | 3 | |
| α-helix | 186-193 | 8 | |
| α-helix | 197-211 | 15 | |
| α-helix | 212-216 | 5 | |
| α-helix | 224-236 | 13 | |
| α-helix | 237-241 | 5 | |
| α-helix | 246-257 | 12 | |
| α-helix | 259-284 | 26 | |
| α-helix | 299-310 | 12 | |
| α-helix | 323-357 | 35 | |
| α-helix | 358-360 | 3 | |
| α-helix | 361-363 | 3 | |
| α-helix | 364-367 | 4 | |
| α-helix | 368-383 | 16 | |
| α-helix | 390-395 | 6 | |
| α-helix | 510-532 | 23 | |
| α-helix | 535-536 | 2 | |
| α-helix | 538-566 | 29 | |
Chain F: 8 helices, 4 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 7-21 | 15 | |
| β-strand | 28 | 1 | 5 |
| α-helix | 30-40 | 11 | |
| α-helix | 46-56 | 11 | |
| β-strand | 64 | 1 | 5 |
| α-helix | 66-73 | 8 | |
| α-helix | 80-91 | 12 | |
| β-strand | 100-102 | 3 | 6 |
| α-helix | 103-112 | 10 | |
| α-helix | 119-128 | 10 | |
| β-strand | 136-138 | 3 | 6 |
| α-helix | 139-146 | 8 | |
Chain G: 20 helices, 0 β-strands
| Element | Residues | Length | Sheet |
|---|
| α-helix | 106-114 | 9 | |
| α-helix | 121-144 | 24 | |
| α-helix | 149-177 | 29 | |
| α-helix | 178-180 | 3 | |
| α-helix | 186-193 | 8 | |
| α-helix | 197-215 | 19 | |
| α-helix | 224-236 | 13 | |
| α-helix | 237-241 | 5 | |
| α-helix | 246-257 | 12 | |
| α-helix | 259-283 | 25 | |
| α-helix | 299-310 | 12 | |
| α-helix | 323-357 | 35 | |
| α-helix | 358-360 | 3 | |
| α-helix | 361-363 | 3 | |
| α-helix | 364-367 | 4 | |
| α-helix | 368-383 | 16 | |
| α-helix | 390-395 | 6 | |
| α-helix | 510-532 | 23 | |
| α-helix | 535-536 | 2 | |
| α-helix | 538-567 | 30 | |
Molecules and chains
| Molecule | Chains | Type | Length | Organism | UniProt |
|---|
| Calmodulin-1 | B, D, F, H | protein | 149 | Homo sapiens | P0DP23 (AlphaFold model) |
| Potassium voltage-gated channel subfamily KQT member 1 | A, C, E, G | protein | 557 | Homo sapiens | P51787 (AlphaFold model) |
Sequence of entity 1 (B, D, F, H), FASTA
>8SIK_1 Calmodulin-1 (chains B, D, F, H)
MADQLTEEQIAEFKEAFSLFDKDGDGTITTKELGTVMRSLGQNPTEAELQDMINEVDADG
NGTIDFPEFLTMMARKMKDTDSEEEIREAFRVFDKDGNGYISAAELRHVMTNLGEKLTDE
EVDEMIREADIDGDGQVNYEEFVQMMTAK
Sequence of entity 2 (A, C, E, G), FASTA
>8SIK_2 Potassium voltage-gated channel subfamily KQT member 1 (chains A, C, E, G)
MASDLGPRPPVSLDPRVSIYSTRRPVLARTHVQGRVYNFLERPTGWKCFVYHFAVFLIVL
VCLIFSVLSTIEQYAALATGTLFWMEIVLVVFFGTEYVVRLWSAGCRSKYVGLWGRLRFA
RKPISIIDLIVVVASMVVLCVGSKGQVFATSAIRGIRFLQILRMLHVDRQGGTWRLLGSV
VFIHRQELITTLYIGFLGLIFSSYFVYLAEKDAVNESGRVEFGSYADALWWGVVTVTTIG
YGDKVPQTWVGKTIASCFSVFAISFFALPAGILGSGFALKVQQKQRQKHFNRQIPAAASL
IQTAWRCYAAENPDSSTWKIYIRKAPRSHTLLSPSPKPKKSVVVKKKKFKLDKDNGVTPG
EKMLTVPHITCDPPEERRLDHFSVDGYDSSVRKSPTLLEVSMPHFMRTNSFAEDLDLEGE
TLLTPITHISQLREHHRATIKVIRRMQYFVAKKKFQQARKPYDVRDVIEQYSQGHLNLMV
RIKELQRRLDQSIGKPSLFISVSEKSKDRGSNTIGARLNRVEDKVTQLDQRLALITDMLH
QLLSLHSNSLEVLFQGP
Ligands and cofactors
| ID | Name | Formula | Copies |
|---|
| CA | Calcium ion | Ca | 8 |
Primary citation
The membrane electric field regulates the PIP 2 -binding site to gate the KCNQ1 channel. Mandala, V.S., MacKinnon, R. Proc Natl Acad Sci U S A (2023) 120:e2301985120-e2301985120. DOI 10.1073/pnas.2301985120 · PubMed
Other PDB entries of the same protein (UniProt P0DP23 (AlphaFold model), which also has an AlphaFold model), best resolution first:
- 9MXD 1.17 Å, Human E104A calmodulin:MLCK RM20 complex
- 7BF1 1.24 Å, Ca2+-Calmodulin in complex with peptide from brain-type creatine kinase in extended 1:2…
- 6XXX 1.25 Å, 1.25 Angstrom crystal structure of Ca/CaM A102V:RyR2 peptide complex
- 4DJC 1.35 Å, 1.35 A crystal structure of the NaV1.5 DIII-IV-Ca/CaM complex
- 7BF2 1.43 Å, Ca2+-Calmodulin in complex with human muscle form creatine kinase peptide in extended…
- 2F3Y 1.45 Å, Calmodulin/IQ domain complex
- 2W73 1.45 Å, High-resolution structure of the complex between calmodulin and a peptide from…
- 4LZX 1.5 Å, Complex of IQCG and Ca2+-free CaM
- 5V03 1.58 Å, A positive allosteric modulator binding pocket in SK2 ion channels is shared by Riluzole…
- 9MVW 1.58 Å, Crystal structure of S101F calmodulin - CaM:RM20 analog complex
- 2F3Z 1.6 Å, Calmodulin/IQ-AA domain complex
- 6M7H 1.6 Å, Structure of calmodulin with KN93
Browse structure collections
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