9L8W: Human KCNQ2-CaM

Human KCNQ2-CaM in complex with QO-58. Determined by electron microscopy at 2.9 Å resolution. Released 21 Jan 2026.

Method: Electron microscopy
Resolution: 2.9 Å
Organism: Homo sapiens
Chains: 4
Atoms: 8,604
Mol. weight: 387.45 kDa
Ligands: A1LVR
Released: 21 Jan 2026

Explore 9L8W in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

9L8W contains 47 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.

Chain A: 11 helices, 0 β-strands

Element	Residues	Length
α-helix	71-85	15
α-helix	92-114	23
α-helix	116-147	32
α-helix	156-164	9
α-helix	167-181	15
α-helix	182-186	5
α-helix	194-210	17
α-helix	216-227	12
α-helix	229-253	25
α-helix	264-275	12
α-helix	288-327	40

Chains B, C and D: 12 helices, 0 β-strands

Element	Residues	Length
α-helix	71-85	15
α-helix	92-114	23
α-helix	116-147	32
α-helix	156-164	9
α-helix	167-181	15
α-helix	182-186	5
α-helix	192-193	2
α-helix	194-209	16
α-helix	216-227	12
α-helix	229-253	25
α-helix	264-275	12
α-helix	288-327	40

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

>9L8W_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

Ligands and cofactors

ID	Name	Formula	Copies
A1LVR	QO-58	C18 H8 Cl2 F4 N4 O	8

Primary citation

Structure basis for the activation of KCNQ2 by endogenous and exogenous ligands. Zhao, Y., Yang, Z., Shi, S. et al. Cell Rep (2025) 45:116771-116771. DOI 10.1016/j.celrep.2025.116771 · PubMed

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

22AY 2.3 Å, KCNQ2 homotetramer in apo state
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

Browse structure collections

About this viewer

MolViewer shows 9L8W directly in your browser with nothing to install. Switch between cartoon, ball-and-stick, spacefill and surface views, color by chain, secondary structure or B-factor, measure distances, angles and dihedrals, and share or embed the view.