9YAQ | pdb_00009yaq

The structure of the cardiac native cross bridge in the rigor state, myosin heads bound to actin molecules 5 and 6.

PDB DOI: https://doi.org/10.2210/pdb9YAQ/pdb
EM Map EMD-72734: EMDB EMDataResource

Classification: MOTOR PROTEIN
Organism(s): Sus scrofa
Expression System: Sus scrofa
Mutation(s): No

Deposited: 2025-09-16 Released: 2026-07-22
Deposition Author(s): Galkin, V.E., Risi, C.M.
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)

Experimental Data Snapshot

Method: ELECTRON MICROSCOPY
Resolution: 4.63 Å
Aggregation State: FILAMENT
Reconstruction Method: SINGLE PARTICLE

Starting Models: experimental
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wwPDB Validation 3D Report Full Report

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

Literature

The structure of the native cardiac cross-bridge

Galkin, V.E., Risi, C.M.

To be published.

Macromolecule Content

Total Structure Weight: 902.55 kDa
Atom Count: 33,966
Modeled Residue Count: 4,239
Deposited Residue Count: 7,848
Unique protein chains: 7

Macromolecules

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| 3D Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Actin, alpha cardiac muscle 1	A, B, C, D	377	Sus scrofa	Mutation(s): 0 Gene Names: ACTC1
UniProt
Find proteins for B6VNT8 (Sus scrofa) Explore B6VNT8 Go to UniProtKB: B6VNT8
Entity Groups
Sequence Clusters	30% Identity 50% Identity 70% Identity 90% Identity 95% Identity 100% Identity
UniProt Group	B6VNT8
Sequence Annotations Expand
Reference Sequence

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| 3D Structure

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Tropomyosin alpha-1 chain	E, F, G, H	284	Sus scrofa	Mutation(s): 0 Gene Names: TPM1
UniProt
Find proteins for P42639 (Sus scrofa) Explore P42639 Go to UniProtKB: P42639
Entity Groups
Sequence Clusters	30% Identity 50% Identity 70% Identity 90% Identity 95% Identity 100% Identity
UniProt Group	P42639
Sequence Annotations Expand
Reference Sequence

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| 3D Structure

Entity ID: 3
Molecule	Chains	Sequence Length	Organism	Details	Image
Troponin T2, cardiac type	I, P	285	Sus scrofa	Mutation(s): 0 Gene Names: TNNT2
UniProt
Find proteins for A0A5G2Q8N0 (Sus scrofa) Explore A0A5G2Q8N0 Go to UniProtKB: A0A5G2Q8N0
Entity Groups
Sequence Clusters	30% Identity 50% Identity 70% Identity 90% Identity 95% Identity 100% Identity
UniProt Group	A0A5G2Q8N0
Sequence Annotations Expand
Reference Sequence

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| 3D Structure

Entity ID: 4
Molecule	Chains	Sequence Length	Organism	Details	Image
Myosin-7	J, K	1,935	Sus scrofa	Mutation(s): 0 Gene Names: MYH7
UniProt
Find proteins for P79293 (Sus scrofa) Explore P79293 Go to UniProtKB: P79293
Entity Groups
Sequence Clusters	30% Identity 50% Identity 70% Identity 90% Identity 95% Identity 100% Identity
UniProt Group	P79293
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Reference Sequence

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| 3D Structure

Entity ID: 5
Molecule	Chains	Sequence Length	Organism	Details	Image
Myosin light chain 3	L, M	196	Sus scrofa	Mutation(s): 0 Gene Names: MYL3
UniProt
Find proteins for F1SNW4 (Sus scrofa) Explore F1SNW4 Go to UniProtKB: F1SNW4
Entity Groups
Sequence Clusters	30% Identity 50% Identity 70% Identity 90% Identity 95% Identity 100% Identity
UniProt Group	F1SNW4
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Reference Sequence

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| 3D Structure

Entity ID: 6
Molecule	Chains	Sequence Length	Organism	Details	Image
Troponin C, slow skeletal and cardiac muscles	N	161	Sus scrofa	Mutation(s): 0 Gene Names: TNNC1, TNNC
UniProt
Find proteins for P63317 (Sus scrofa) Explore P63317 Go to UniProtKB: P63317
Entity Groups
Sequence Clusters	30% Identity 50% Identity 70% Identity 90% Identity 95% Identity 100% Identity
UniProt Group	P63317
Sequence Annotations Expand
Reference Sequence

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| 3D Structure

Entity ID: 7
Molecule	Chains	Sequence Length	Organism	Details	Image
Troponin I, cardiac muscle	O	211	Sus scrofa	Mutation(s): 0 Gene Names: TNNI3
UniProt
Find proteins for A5X5T5 (Sus scrofa) Explore A5X5T5 Go to UniProtKB: A5X5T5
Entity Groups
Sequence Clusters	30% Identity 50% Identity 70% Identity 90% Identity 95% Identity 100% Identity
UniProt Group	A5X5T5
Sequence Annotations Expand
Reference Sequence

Small Molecules

Ligands 3 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram	3D Interactions
ADP Query on ADP Download:Ideal Coordinates CCD File SDF format, chain W [auth D] SDF format, chain U [auth C] SDF format, chain S [auth B] SDF format, chain Q [auth A] MOL2 format, chain W [auth D] MOL2 format, chain U [auth C] MOL2 format, chain S [auth B] MOL2 format, chain Q [auth A] mmCIF format, chain W [auth D] mmCIF format, chain U [auth C] mmCIF format, chain S [auth B] mmCIF format, chain Q [auth A]	Q [auth A], S [auth B], U [auth C], W [auth D]	ADENOSINE-5'-DIPHOSPHATE C₁₀ H₁₅ N₅ O₁₀ P₂ XTWYTFMLZFPYCI-KQYNXXCUSA-N		Interactions Focus chain Q [auth A] Focus chain S [auth B] Focus chain U [auth C] Focus chain W [auth D] Interactions & Density Focus chain Q [auth A] Focus chain S [auth B] Focus chain U [auth C] Focus chain W [auth D]
CA Query on CA Download:Ideal Coordinates CCD File SDF format, chain Z [auth N] SDF format, chain Y [auth N] SDF format, chain AA [auth N] MOL2 format, chain Z [auth N] MOL2 format, chain Y [auth N] MOL2 format, chain AA [auth N] mmCIF format, chain Z [auth N] mmCIF format, chain Y [auth N] mmCIF format, chain AA [auth N]	AA [auth N], Y [auth N], Z [auth N]	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N		Interactions Focus chain AA [auth N] Focus chain Y [auth N] Focus chain Z [auth N] Interactions & Density Focus chain AA [auth N] Focus chain Y [auth N] Focus chain Z [auth N]
MG Query on MG Download:Ideal Coordinates CCD File SDF format, chain X [auth D] SDF format, chain V [auth C] SDF format, chain T [auth B] SDF format, chain R [auth A] MOL2 format, chain X [auth D] MOL2 format, chain V [auth C] MOL2 format, chain T [auth B] MOL2 format, chain R [auth A] mmCIF format, chain X [auth D] mmCIF format, chain V [auth C] mmCIF format, chain T [auth B] mmCIF format, chain R [auth A]	R [auth A], T [auth B], V [auth C], X [auth D]	MAGNESIUM ION Mg JLVVSXFLKOJNIY-UHFFFAOYSA-N		Interactions Focus chain R [auth A] Focus chain T [auth B] Focus chain V [auth C] Focus chain X [auth D] Interactions & Density Focus chain R [auth A] Focus chain T [auth B] Focus chain V [auth C] Focus chain X [auth D]

Experimental Data & Validation

Experimental Data

Method: ELECTRON MICROSCOPY
Resolution: 4.63 Å
Aggregation State: FILAMENT
Reconstruction Method: SINGLE PARTICLE

EM Software:

Task	Software Package	Version
MODEL REFINEMENT	PHENIX
RECONSTRUCTION	RELION	3.1

Structure Validation

View Full Validation Report

View more in-depth experimental data

Entry History

& Funding Information

Deposition Data

Released Date: 2026-07-22

Deposition Author(s):

Galkin, V.E.

Risi, C.M.

Funding Organization	Location	Grant Number
National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)	United States	R01HL160966
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)	United States	R01GM120137

Revision History (Full details and data files)

Version 1.0: 2026-07-22
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.

9YAQ | pdb_00009yaq

The structure of the cardiac native cross bridge in the rigor state, myosin heads bound to actin molecules 5 and 6.

Literature

The structure of the native cardiac cross-bridge

Biological Assembly 1

Macromolecules

Entity ID: 1

UniProt

Entity Groups

Sequence Annotations

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Entity ID: 2

UniProt

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Entity ID: 3

UniProt

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Entity ID: 4

UniProt

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Entity ID: 5

UniProt

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Entity ID: 6

UniProt

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Entity ID: 7

UniProt

Entity Groups

Sequence Annotations

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Small Molecules

Experimental Data & Validation

Experimental Data

Structure Validation

Entry History

Deposition Data

Revision History (Full details and data files)