22AY: KCNQ2 homotetramer in apo state

KCNQ2 homotetramer in apo state. Determined by electron microscopy at 2.3 Å resolution. Released 3 Jun 2026.

Method: Electron microscopy
Resolution: 2.3 Å
Organism: Homo sapiens
Chains: 4
Atoms: 8,156
Mol. weight: 384.06 kDa
Released: 3 Jun 2026

Explore 22AY in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

22AY contains 60 α-helices and 0 β-strands across 4 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.

Chains A, B, C and D: 15 helices, 0 β-strands

Element	Residues	Length
α-helix	71-85	15
α-helix	90-92	3
α-helix	93-113	21
α-helix	119-147	29
α-helix	148-150	3
α-helix	152-154	3
α-helix	156-164	9
α-helix	167-183	17
α-helix	196-204	9
α-helix	205-210	6
α-helix	213-215	3
α-helix	216-227	12
α-helix	229-254	26
α-helix	264-275	12
α-helix	288-328	41

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Potassium voltage-gated channel subfamily KQT member 2	A, B, C, D	protein	872	Homo sapiens	O43526 (AlphaFold model)

Sequence of entity 1 (A, B, C, D), FASTA

>22AY_1 Potassium voltage-gated channel subfamily KQT member 2 (chains A, B, C, D)
MVQKSRNGGVYPGPSGEKKLKVGFVGLDPGAPDSTRDGALLIAGSEAPKRGSILSKPRAG
GAGAGKPPKRNAFYRKLQNFLYNVLERPRGWAFIYHAYVFLLVFSCLVLSVFSTIKEYEK
SSEGALYILEIVTIVVFGVEYFVRIWAAGCCCRYRGWRGRLKFARKPFCVIDIMVLIASI
AVLAAGSQGNVFATSALRSLRFLQILRMIRMDRRGGTWKLLGSVVYAHSKELVTAWYIGF
LCLILASFLVYLAEKGENDHFDTYADALWWGLITLTTIGYGDKYPQTWNGRLLAATFTLI
GVSFFALPAGILGSGFALKVQEQHRQKHFEKRRNPAAGLIQSAWRFYATNLSRTDLHSTW
QYYERTVTVPMYSSQTQTYGASRLIPPLNQLELLRNLKSKSGLAFRKDPPPEPSPSKGSP
CRGPLCGCCPGRSSQKVSLKDRVFSSPRGVAAKGKGSPQAQTVRRSPSADQSLEDSPSKV
PKSWSFGDRSRARQAFRIKGAASRQNSEEASLPGEDIVDDKSCPCEFVTEDLTPGLKVSI
RAVCVMRFLVSKRKFKESLRPYDVMDVIEQYSAGHLDMLSRIKSLQSRVDQIVGRGPAIT
DKDRTKGPAEAELPEDPSMMGRLGKVEKQVLSMEKKLDFLVNIYMQRMGIPPTETEAYFG
AKEPEPAPPYHSPEDSREHVDRHGCIVKIVRSSSSTGQKNFSAPPAAPPVQCPPSTSWQP
QSHPRQGHGTSPVGDHGSLVRIPPPPAHERSLSAYGGGNRASMEFLRQEDTPGCRPPEGN
LRDSDTSISIPSVDHEELERSFSGFSISQSKENLDALNSCYAAVAPCAKVRPYIAEGESD
TDSDLCTPCGPPPRSATGEGPFGDVGWAGPRK

Primary citation

Structural basis for the assembly and modulation of human M-channels. Lu, F., Huang, X., Cai, G. et al. To be published.

Other PDB entries of the same protein (UniProt O43526 (AlphaFold model), which also has an AlphaFold model), best resolution first:

22BJ 2.4 Å, KCNQ2/3 heterotetramer with 3:1 stoichiometry
22BF 2.5 Å, XEN1101 bound KCNQ2/3 heteromer with 3:1 stoichiometry, state 2
22BG 2.5 Å, XEN1101 bound KCNQ2/3 heteromer with 3:1 stoichiometry, state 3
8IZY 2.5 Å, Human KCNQ2-CaM in complex with HN37
22BE 2.6 Å, XEN1101 bound KCNQ2/3 heteromer with 3:1 stoichiometry, state 1
22BI 2.6 Å, XEN1101 bound KCNQ2/3 heteromer with 2:2 stoichiometry
22AZ 2.7 Å, ICA-1103811 bound KCNQ2/3 heteromer with 3:1 stoichiometry, state 1
22BK 2.7 Å, KCNQ2/3 heterotetramer with 2:2 stoichiometry
8J03 2.7 Å, Human KCNQ2(F104A)-CaM-PIP2-CBD complex in state I
8J04 2.7 Å, Human KCNQ2-CaM-HN37 complex in the presence of PIP2
8J05 2.7 Å, Human KCNQ2-CaM complex in the presence of PIP2
22BC 2.8 Å, ICA-1103811 bound KCNQ2/3 heteromer with 3:1 stoichiometry, state 3

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