9B3R: Human cardiac F-actin

The structure of human cardiac F-actin. Determined by electron microscopy at 3.5 Å resolution. Released 29 May 2024.

Method: Electron microscopy
Resolution: 3.5 Å
Organism: Homo sapiens
Chains: 3
Atoms: 8,808
Mol. weight: 127.59 kDa
Ligands: ADP, MG
Released: 29 May 2024

Explore 9B3R in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

9B3R contains 63 α-helices and 58 β-strands across 3 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: 20 helices, 19 β-strands

Element	Residues	Length	Sheet
β-strand	8-12	5	1
β-strand	16-21	6	1
β-strand	29-32	4	1
β-strand	35-36	2	2
β-strand	53-54	2	2
α-helix	56-59	4
β-strand	68	1	2
β-strand	71-72	2	3
β-strand	75-76	2	3
α-helix	79-87	9
α-helix	88-94	7
β-strand	103-107	5	1
α-helix	113-125	13
β-strand	131-136	6	1
α-helix	137-145	9
β-strand	150-155	6	4
β-strand	160-166	7	4
β-strand	169-170	2	4
α-helix	172-174	3
β-strand	177-178	2	4
α-helix	182-192	11
α-helix	203-216	14
α-helix	224-231	8
β-strand	238-241	4	5
β-strand	247-250	4	5
α-helix	253-259	7
α-helix	264-267	4
α-helix	274-283	10
α-helix	290-295	6
β-strand	297-300	4	4
α-helix	303-305	3
α-helix	309-318	10
β-strand	329-330	2	4
α-helix	338-348	11
α-helix	351-354	4
β-strand	357-358	2	1
α-helix	359-365	7
α-helix	366-368	3
α-helix	369-373	5

Chain D: 22 helices, 18 β-strands

Element	Residues	Length	Sheet
β-strand	8-12	5	6
β-strand	16-21	6	6
β-strand	29-32	4	6
β-strand	35-36	2	7
β-strand	53-54	2	7
α-helix	56-60	5
β-strand	68	1	7
β-strand	71-72	2	8
β-strand	75-76	2	8
α-helix	79-87	9
α-helix	88-93	6
α-helix	98-100	3
β-strand	103-106	4	6
α-helix	113-125	13
β-strand	132-135	4	6
α-helix	137-144	8
β-strand	150-155	6	9
β-strand	160-165	6	9
β-strand	170	1	9
α-helix	172-174	3
β-strand	177-178	2	9
α-helix	182-192	11
α-helix	193-195	3
α-helix	203-216	14
α-helix	223-231	9
β-strand	238-241	4	10
β-strand	247-250	4	10
α-helix	253-256	4
α-helix	258-261	4
α-helix	264-267	4
α-helix	274-283	10
α-helix	290-294	5
β-strand	297-300	4	9
α-helix	303-305	3
α-helix	309-318	10
β-strand	329-330	2	9
α-helix	338-348	11
α-helix	352-354	3
α-helix	359-365	7
α-helix	369-376	6

Chain E: 21 helices, 21 β-strands

Element	Residues	Length	Sheet
β-strand	8-9	2	11
β-strand	11-12	2	12
β-strand	16-19	4	12
β-strand	21	1	11
β-strand	29-32	4	12
β-strand	35-36	2	13
β-strand	53-54	2	13
α-helix	56-59	4
β-strand	68	1	13
β-strand	71-72	2	14
β-strand	75-76	2	14
α-helix	79-87	9
α-helix	88-94	7
β-strand	103-106	4	11
α-helix	113-125	13
β-strand	131-135	5	11
α-helix	137-145	9
β-strand	150-155	6	15
β-strand	160-165	6	15
β-strand	170	1	15
α-helix	172-174	3
β-strand	177-178	2	15
α-helix	182-192	11
α-helix	193-195	3
α-helix	203-216	14
α-helix	223-231	9
β-strand	238-241	4	16
β-strand	247-250	4	16
α-helix	253-256	4
α-helix	258-261	4
α-helix	264-267	4
α-helix	274-283	10
α-helix	290-294	5
β-strand	297-300	4	15
α-helix	303-305	3
α-helix	309-318	10
β-strand	329-330	2	15
α-helix	338-348	11
α-helix	351-355	5
β-strand	357-358	2	11
α-helix	359-365	7
α-helix	369-376	6

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Actin, alpha cardiac muscle 1	A, D, E	protein	377	Homo sapiens	P68032 (AlphaFold model)

Sequence of entity 1 (A, D, E), FASTA

>9B3R_1 Actin, alpha cardiac muscle 1 (chains A, D, E)
MCDDEETTALVCDNGSGLVKAGFAGDDAPRAVFPSIVGRPRHQGVMVGMGQKDSYVGDEA
QSKRGILTLKYPIEHGIITNWDDMEKIWHHTFYNELRVAPEEHPTLLTEAPLNPKANREK
MTQIMFETFNVPAMYVAIQAVLSLYASGRTTGIVLDSGDGVTHNVPIYEGYALPHAIMRL
DLAGRDLTDYLMKILTERGYSFVTTAEREIVRDIKEKLCYVALDFENEMATAASSSSLEK
SYELPDGQVITIGNERFRCPETLFQPSFIGMESAGIHETTYNSIMKCDIDIRKDLYANNV
LSGGTTMYPGIADRMQKEITALAPSTMKIKIIAPPERKYSVWIGGSILASLSTFQQMWIS
KQEYDEAGPSIVHRKCF

Ligands and cofactors

ID	Name	Formula	Copies
ADP	Adenosine-5'-diphosphate	C10 H15 N5 O10 P2	3
MG	Magnesium ion	Mg	3

Primary citation

The hypertrophic cardiomyopathy-associated A331P actin variant enhances basal contractile activity and elicits resting muscle dysfunction. Doran, M.H., Rynkiewicz, M.J., Despond, E. et al. iScience (2025) 28:111816-111816. DOI 10.1016/j.isci.2025.111816 · PubMed

Other PDB entries of the same protein (UniProt P68032 (AlphaFold model), which also has an AlphaFold model), best resolution first:

8GT1 1.35 Å, Crystal structure of human cardiac alpha actin A108G mutant (ADP-Pi state) in complex…
8GSW 1.4 Å, Crystal structure of human cardiac alpha actin A108G mutant (AMPPNP state) in complex…
8GT5 1.4 Å, Crystal structure of human cardiac alpha actin Q137A mutant (ADP-Pi state) in complex…
8GSU 1.5 Å, Crystal structure of human cardiac alpha actin (WT_ADP-Pi) in complex with fragmin F1…
8GT2 1.5 Å, Crystal structure of human cardiac alpha actin P109A mutant (AMPPNP state) in complex…
8GT3 1.5 Å, Crystal structure of human cardiac alpha actin P109A mutant (ADP-Pi state) in complex…
8GT4 1.55 Å, Crystal structure of human cardiac alpha actin Q137A mutant (AMPPNP state) in complex…
9ZBL 2.79 Å, Helical Reconstruction of the Human Cardiac F-Actin-Tropomyosin Complex
8ZI9 3.08 Å, Human left ventricle actin and myosin complex
9BPH 3.12 Å, cryo-EM structure of cardiac muscle alpha-actin M305L hcm mutant
9ZBP 3.12 Å, Helical Reconstruction of the Complex of Pseudo-Acetylated Human Cardiac Actin…
8ZB7 3.19 Å, Human left ventricle ATM complex

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