9UJ4 | pdb_00009uj4

Structure of human KCNQ1-CaM complex

PDB DOI: https://doi.org/10.2210/pdb9UJ4/pdb
EM Map EMD-64213: EMDB EMDataResource

Classification: MEMBRANE PROTEIN
Organism(s): Homo sapiens
Expression System: Homo sapiens
Mutation(s): No

Deposited: 2025-04-16 Released: 2026-04-22
Deposition Author(s): Hou, P.P., Zhang, J., Cheng, X.Y., Wan, S.Y., Zhong, L., Hu, B.
Funding Organization(s): Not funded

Experimental Data Snapshot

Method: ELECTRON MICROSCOPY
Resolution: 2.59 Å
Aggregation State: PARTICLE
Reconstruction Method: SINGLE PARTICLE

wwPDB Validation 3D Report Full Report

Validation slider image for 9UJ4

This is version 1.0 of the entry. See complete history.

Literature

Structure of human KCNQ1-CaM complex

Hou, P.P., Zhang, J., Cheng, X.Y., Wan, S.Y., Hu, B., Zhong, L.

To be published.

Macromolecule Content

Total Structure Weight: 370.25 kDa
Atom Count: 15,968
Modeled Residue Count: 1,972
Deposited Residue Count: 3,300
Unique protein chains: 2

Macromolecules

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Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Potassium voltage-gated channel subfamily KQT member 1	A, D [auth G], F [auth E], H [auth C]	676	Homo sapiens	Mutation(s): 0 Gene Names: KCNQ1, KCNA8, KCNA9, KVLQT1
UniProt & NIH Common Fund Data Resources
Find proteins for P51787 (Homo sapiens) Explore P51787 Go to UniProtKB: P51787
PHAROS: P51787 GTEx: ENSG00000053918
Entity Groups
Sequence Clusters	30% Identity 50% Identity 70% Identity 90% Identity 95% Identity 100% Identity
UniProt Group	P51787
Sequence Annotations Expand
Reference Sequence

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Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Calmodulin-1	B, C [auth H], E [auth F], G [auth D]	149	Homo sapiens	Mutation(s): 0 Gene Names: CALM1, CALM, CAM, CAM1
UniProt & NIH Common Fund Data Resources
Find proteins for P0DP23 (Homo sapiens) Explore P0DP23 Go to UniProtKB: P0DP23
PHAROS: P0DP23 GTEx: ENSG00000198668
Entity Groups
Sequence Clusters	30% Identity 50% Identity 70% Identity 90% Identity 95% Identity 100% Identity
UniProt Group	P0DP23
Sequence Annotations Expand
Reference Sequence

Small Molecules

Ligands 3 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram	3D Interactions
PC1 (Subject of Investigation/LOI) Query on PC1 Download:Ideal Coordinates CCD File SDF format, chain M [auth A] SDF format, chain R [auth G] SDF format, chain U [auth E] SDF format, chain X [auth C] MOL2 format, chain M [auth A] MOL2 format, chain R [auth G] MOL2 format, chain U [auth E] MOL2 format, chain X [auth C] mmCIF format, chain M [auth A] mmCIF format, chain R [auth G] mmCIF format, chain U [auth E] mmCIF format, chain X [auth C]	M [auth A], R [auth G], U [auth E], X [auth C]	1,2-DIACYL-SN-GLYCERO-3-PHOSPHOCHOLINE C₄₄ H₈₈ N O₈ P NRJAVPSFFCBXDT-HUESYALOSA-N		Interactions Focus chain M [auth A] Focus chain R [auth G] Focus chain U [auth E] Focus chain X [auth C] Interactions & Density Focus chain M [auth A] Focus chain R [auth G] Focus chain U [auth E] Focus chain X [auth C]
CA (Subject of Investigation/LOI) Query on CA Download:Ideal Coordinates CCD File SDF format, chain N [auth B] SDF format, chain O [auth B] SDF format, chain P [auth H] SDF format, chain Q [auth H] SDF format, chain S [auth F] SDF format, chain T [auth F] SDF format, chain V [auth D] SDF format, chain W [auth D] MOL2 format, chain N [auth B] MOL2 format, chain O [auth B] MOL2 format, chain P [auth H] MOL2 format, chain Q [auth H] MOL2 format, chain S [auth F] MOL2 format, chain T [auth F] MOL2 format, chain V [auth D] MOL2 format, chain W [auth D] mmCIF format, chain N [auth B] mmCIF format, chain O [auth B] mmCIF format, chain P [auth H] mmCIF format, chain Q [auth H] mmCIF format, chain S [auth F] mmCIF format, chain T [auth F] mmCIF format, chain V [auth D] mmCIF format, chain W [auth D]	N [auth B] O [auth B] P [auth H] Q [auth H] S [auth F] N [auth B], O [auth B], P [auth H], Q [auth H], S [auth F], T [auth F], V [auth D], W [auth D]	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N		Interactions Focus chain N [auth B] Focus chain O [auth B] Focus chain P [auth H] Focus chain Q [auth H] Focus chain S [auth F] Focus chain T [auth F] Focus chain V [auth D] Focus chain W [auth D] Interactions & Density Focus chain N [auth B] Focus chain O [auth B] Focus chain P [auth H] Focus chain Q [auth H] Focus chain S [auth F] Focus chain T [auth F] Focus chain V [auth D] Focus chain W [auth D]
K (Subject of Investigation/LOI) Query on K Download:Ideal Coordinates CCD File SDF format, chain K [auth A] SDF format, chain L [auth A] SDF format, chain J [auth A] SDF format, chain I [auth A] MOL2 format, chain K [auth A] MOL2 format, chain L [auth A] MOL2 format, chain J [auth A] MOL2 format, chain I [auth A] mmCIF format, chain K [auth A] mmCIF format, chain L [auth A] mmCIF format, chain J [auth A] mmCIF format, chain I [auth A]	I [auth A], J [auth A], K [auth A], L [auth A]	POTASSIUM ION K NPYPAHLBTDXSSS-UHFFFAOYSA-N		Interactions Focus chain I [auth A] Focus chain J [auth A] Focus chain K [auth A] Focus chain L [auth A] Interactions & Density Focus chain I [auth A] Focus chain J [auth A] Focus chain K [auth A] Focus chain L [auth A]

Experimental Data & Validation

Experimental Data

Method: ELECTRON MICROSCOPY
Resolution: 2.59 Å
Aggregation State: PARTICLE
Reconstruction Method: SINGLE PARTICLE

Structure Validation

View Full Validation Report

View more in-depth experimental data

Entry History

& Funding Information

Deposition Data

Released Date: 2026-04-22

Deposition Author(s):

Funding Organization	Location	Grant Number
Not funded		--

Revision History (Full details and data files)

Version 1.0: 2026-04-22
Type: Initial release

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RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM157729. RCSB PDB uses resources of the National Energy Research Scientific Computing Center (NERSC), a Department of Energy User Facility.