10NK | pdb_000010nk

Xenopus KCNQ1 Intermediate State (E1R/R2E) in complex with UCL2077

• PDB DOI: https://doi.org/10.2210/pdb10NK/pdb
• EM Map EMD-75305: EMDB EMDataResource

• Classification: TRANSPORT PROTEIN
• Organism(s): Homo sapiens, Xenopus laevis
• Expression System: Homo sapiens
• Mutation(s): Yes 


• Deposited: 2026-01-28 Released: 2026-09-02 
• Deposition Author(s): Kyriakis, E., Eldstrom, J., Van Petegem, F., Fedida, D.
• Funding Organization(s): Canadian Institutes of Health Research (CIHR), Natural Sciences and Engineering Research Council (NSERC, Canada), Other private, Other government

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 3.95 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Literature

Structural and kinetic mechanisms of state-dependent potassium channel inhibition

Kyriakis, E., Roscioni, A., Eldstrom, J., Sastre, D., Dou, Y., Taddei, A., Molinarolo, S., Tian, M., Maragliano, L., Van Petegem, F., Fedida, D.

(2026) Sci Adv 

Biological Assembly 1  

Global Symmetry: Cyclic - C4  (Explore in 3D)
Global Stoichiometry: Hetero 8-mer - A4B4 

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: electron microscopy

Macromolecule Content 

• Total Structure Weight: 317.61 kDa 
• Atom Count: 14,500 
• Modeled Residue Count: 1,880 
• Deposited Residue Count: 2,776 
• Unique protein chains: 2

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Calmodulin-1	A [auth B], B [auth D], E [auth C], F [auth E]	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:  ENSG00000143933 ENSG00000160014 ENSG00000198668

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Potassium voltage-gated channel subfamily KQT member 1	C [auth A], D [auth G], G [auth F], H	545	Xenopus laevis	Mutation(s): 2  Gene Names: kcnq1, kvlqt1
UniProt
Find proteins for P70057 (Xenopus laevis) Explore P70057  Go to UniProtKB:  P70057

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
A1C6W( Subject of Investigation/LOI)	I [auth A], J [auth F]	1,1,1-triphenyl-N-[(pyridin-3-yl)methyl]methanamine C25 H22 N2 PQFNWDHABGBCHB-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 3.95 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

EM Software:

Task	Software Package	Version
RECONSTRUCTION	cryoSPARC	4.6.0

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2026-09-02 
Deposition Author(s): Kyriakis, E., Eldstrom, J., Van Petegem, F., Fedida, D.

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Funding Organization	Location	Grant Number
Canadian Institutes of Health Research (CIHR)	Canada	PJT-174999
Natural Sciences and Engineering Research Council (NSERC, Canada)	Canada	RGPIN-2022-03021
Canadian Institutes of Health Research (CIHR)	Canada	PJT-156181
Canadian Institutes of Health Research (CIHR)	Canada	PJT-518041
Other private		G-21-0031566
Other private		G-24-0036478
Other government		RT-2022-2735

Revision History  

• Version 1.0: 2026-09-02
  Type: Initial release