12DK | pdb_000012dk

structure of human KCNQ1-CaM-PIP2 intermediate state

PDB DOI: https://doi.org/10.2210/pdb12DK/pdb
EM Map EMD-76332: EMDB EMDataResource

Classification: MEMBRANE PROTEIN
Organism(s): Homo sapiens
Expression System: Homo sapiens
Mutation(s): Yes

Deposited: 2026-03-28 Released: 2026-05-06
Deposition Author(s): Cui, C., Kermani, A., Sun, J.
Funding Organization(s): National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI), National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS), Ministry of Education (MoE, Singapore)

Experimental Data Snapshot

Method: ELECTRON MICROSCOPY
Resolution: 3.47 Å
Aggregation State: PARTICLE
Reconstruction Method: SINGLE PARTICLE

wwPDB Validation 3D Report Full Report

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

Literature

PIP2 activation of the cardiac IKs potassium channel

Cui, C., Kermani, A., Sun, J.

To be published.

Macromolecule Content

Total Structure Weight: 319.7 kDa
Atom Count: 15,464
Modeled Residue Count: 1,924
Deposited Residue Count: 2,776
Unique protein chains: 2

Macromolecules

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| 3D Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Potassium voltage-gated channel subfamily KQT member 1	A, F [auth C], G [auth E], H [auth G]	545	Homo sapiens	Mutation(s): 3 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

Find similar proteins by:

| 3D Structure

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Calmodulin-1	B, C [auth D], D [auth F], E [auth H]	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 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram	3D Interactions
PT5 (Subject of Investigation/LOI) Query on PT5 Download:Ideal Coordinates CCD File SDF format, chain T [auth G] SDF format, chain S [auth E] SDF format, chain R [auth C] SDF format, chain I [auth A] MOL2 format, chain T [auth G] MOL2 format, chain S [auth E] MOL2 format, chain R [auth C] MOL2 format, chain I [auth A] mmCIF format, chain T [auth G] mmCIF format, chain S [auth E] mmCIF format, chain R [auth C] mmCIF format, chain I [auth A]	I [auth A], R [auth C], S [auth E], T [auth G]	[(2R)-1-octadecanoyloxy-3-[oxidanyl-[(1R,2R,3S,4R,5R,6S)-2,3,6-tris(oxidanyl)-4,5-diphosphonooxy-cyclohexyl]oxy-phospho ryl]oxy-propan-2-yl] (8Z)-icosa-5,8,11,14-tetraenoate C₄₇ H₈₅ O₁₉ P₃ CNWINRVXAYPOMW-HJBQCNPJSA-N		Interactions Focus chain I [auth A] Focus chain R [auth C] Focus chain S [auth E] Focus chain T [auth G] Interactions & Density Focus chain I [auth A] Focus chain R [auth C] Focus chain S [auth E] Focus chain T [auth G]
CA (Subject of Investigation/LOI) Query on CA Download:Ideal Coordinates CCD File SDF format, chain Q [auth H] SDF format, chain P [auth H] SDF format, chain O [auth F] SDF format, chain N [auth F] SDF format, chain M [auth D] SDF format, chain L [auth D] SDF format, chain K [auth B] SDF format, chain J [auth B] MOL2 format, chain Q [auth H] MOL2 format, chain P [auth H] MOL2 format, chain O [auth F] MOL2 format, chain N [auth F] MOL2 format, chain M [auth D] MOL2 format, chain L [auth D] MOL2 format, chain K [auth B] MOL2 format, chain J [auth B] mmCIF format, chain Q [auth H] mmCIF format, chain P [auth H] mmCIF format, chain O [auth F] mmCIF format, chain N [auth F] mmCIF format, chain M [auth D] mmCIF format, chain L [auth D] mmCIF format, chain K [auth B] mmCIF format, chain J [auth B]	J [auth B] K [auth B] L [auth D] M [auth D] N [auth F] J [auth B], K [auth B], L [auth D], M [auth D], N [auth F], O [auth F], P [auth H], Q [auth H]	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N		Interactions Focus chain J [auth B] Focus chain K [auth B] Focus chain L [auth D] Focus chain M [auth D] Focus chain N [auth F] Focus chain O [auth F] Focus chain P [auth H] Focus chain Q [auth H] Interactions & Density Focus chain J [auth B] Focus chain K [auth B] Focus chain L [auth D] Focus chain M [auth D] Focus chain N [auth F] Focus chain O [auth F] Focus chain P [auth H] Focus chain Q [auth H]

Experimental Data & Validation

Experimental Data

Method: ELECTRON MICROSCOPY
Resolution: 3.47 Å
Aggregation State: PARTICLE
Reconstruction Method: SINGLE PARTICLE

EM Software:

Task	Software Package	Version
RECONSTRUCTION	cryoSPARC
MODEL REFINEMENT	PHENIX

Structure Validation

View Full Validation Report

View more in-depth experimental data

Entry History

& Funding Information

Deposition Data

Released Date: 2026-05-06

Deposition Author(s):

Cui, C.

Kermani, A.

Sun, J.

Funding Organization	Location	Grant Number
National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)	United States	R01HL155398
National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)	United States	R01HL166628
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)	United States	1R35GM136409
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)	United States	2R35GM136409
Ministry of Education (MoE, Singapore)	Singapore	A-8002958-00-00
National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)	United States	R00HL143037