9SZR: Shutdown state non-muscle myosin 2A heads region

shutdown state non-muscle myosin 2A heads region. Determined by electron microscopy at 6.3 Å resolution. Released 22 Oct 2025.

Method: Electron microscopy
Resolution: 6.3 Å
Organisms: Homo sapiens, Gallus gallus, Bos taurus
Chains: 6
Atoms: 36,487
Mol. weight: 528.71 kDa
Ligands: MG, PO4, ADP
Released: 22 Oct 2025

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

Secondary structure: helices and β-sheets

9SZR contains 137 α-helices and 77 β-strands across 6 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: 46 helices, 33 β-strands

Element	Residues	Length	Sheet
α-helix	2-6	5
α-helix	7-9	3
α-helix	14-16	3
α-helix	20-29	10
β-strand	31-35	5	1
β-strand	41-50	10	1
β-strand	53-58	6	1
β-strand	64-68	5	1
β-strand	73-74	2	1
α-helix	75-77	3
β-strand	85	1	2
α-helix	86-88	3
α-helix	94-106	13
β-strand	112	1	3
β-strand	113	1	2
β-strand	118-121	4	3
α-helix	132-137	6
α-helix	150-164	15
β-strand	168-169	2	4
β-strand	172-173	2	3
α-helix	180-194	15
α-helix	206-222	17
β-strand	224	1	5
β-strand	232	1	5
β-strand	236	1	6
β-strand	237-243	7	4
β-strand	249-253	5	4
β-strand	257	1	6
α-helix	261-263	3
β-strand	274	1	5
α-helix	275-283	9
α-helix	286-292	7
α-helix	309-310	2
α-helix	315-329	15
α-helix	333-348	16
β-strand	355-356	2	7
β-strand	363-364	2	7
α-helix	369-378	10
α-helix	382-390	9
β-strand	393-395	3	8
β-strand	400-402	3	8
α-helix	407-437	31
β-strand	446-452	7	4
α-helix	464-481	18
α-helix	482-486	5
α-helix	487-495	9
α-helix	509-516	8
α-helix	524-530	7
α-helix	539-549	11
β-strand	557	1	9
β-strand	568-571	4	9
β-strand	576-579	4	9
α-helix	584-589	6
β-strand	591	1	10
α-helix	594-601	8
α-helix	606-611	6
β-strand	619	1	10
α-helix	646-663	18
β-strand	665-666	2	4
β-strand	669-672	4	3
α-helix	685-695	11
α-helix	697-706	10
β-strand	710-713	4	11
α-helix	714-719	6
α-helix	736-746	11
α-helix	751-753	3
β-strand	754-756	3	11
β-strand	760-763	4	11
α-helix	767-823	57
α-helix	826-832	7
α-helix	835-838	4
α-helix	842-1149	308
α-helix	1151-1568	418
α-helix	1569-1573	5
α-helix	1576-1923	348
α-helix	1933-1937	5
α-helix	1940-1943	4
α-helix	1952-1954	3
α-helix	1956-1959	4

Chain B: 51 helices, 26 β-strands

Element	Residues	Length	Sheet
α-helix	2-5	4
α-helix	6-9	4
α-helix	20-29	10
β-strand	31-34	4	12
β-strand	42-50	9	12
β-strand	53-58	6	12
β-strand	63-66	4	12
β-strand	73-74	2	12
α-helix	78-80	3
β-strand	85	1	13
α-helix	86-88	3
α-helix	94-102	9
β-strand	112-114	3	13
β-strand	117-121	5	13
α-helix	131-134	4
α-helix	150-164	15
β-strand	168-171	4	14
β-strand	172-173	2	13
α-helix	180-197	18
α-helix	206-220	15
β-strand	236-243	8	14
β-strand	249-253	5	14
β-strand	256-257	2	14
α-helix	262-264	3
α-helix	278-281	4
α-helix	286-292	7
α-helix	316-328	13
α-helix	333-349	17
α-helix	369-377	9
α-helix	382-390	9
β-strand	394-396	3	15
β-strand	399-401	3	15
α-helix	407-437	31
α-helix	443-444	2
β-strand	446-452	7	14
α-helix	454-457	4
α-helix	465-481	17
α-helix	482-486	5
α-helix	487-494	8
α-helix	509-513	5
α-helix	524-531	8
α-helix	539-548	10
β-strand	556	1	16
α-helix	563-565	3
β-strand	567	1	17
β-strand	570-571	2	16
β-strand	576-577	2	16
β-strand	580	1	17
α-helix	585-589	5
α-helix	594-601	8
α-helix	606-611	6
α-helix	646-662	17
β-strand	665-666	2	14
β-strand	669-672	4	13
α-helix	685-695	11
α-helix	697-706	10
β-strand	710-713	4	18
α-helix	714-720	7
α-helix	726-728	3
α-helix	736-746	11
α-helix	751-753	3
β-strand	754-756	3	18
β-strand	760-763	4	18
α-helix	767-805	39
α-helix	809-825	17
α-helix	829-834	6
α-helix	839-1147	309
α-helix	1149-1152	4
α-helix	1156-1513	358
α-helix	1518-1593	76
α-helix	1594-1598	5
α-helix	1599-1710	112
α-helix	1711-1715	5
α-helix	1716-1829	114
α-helix	1832-1923	92
α-helix	1929-1932	4
α-helix	1934-1936	3

Chain C: 10 helices, 4 β-strands

Element	Residues	Length	Sheet
α-helix	5-15	11
β-strand	26-27	2	19
α-helix	31-38	8
α-helix	44-50	7
α-helix	57-60	4
β-strand	63-64	2	19
α-helix	66-78	13
α-helix	85-91	7
α-helix	92-95	4
β-strand	103-104	2	20
α-helix	105-113	9
α-helix	121-128	8
β-strand	137-138	2	20
α-helix	140-149	10

Chain D: 9 helices, 4 β-strands

Element	Residues	Length	Sheet
α-helix	5-7	3
α-helix	8-15	8
β-strand	25-27	3	21
α-helix	28-37	10
α-helix	44-49	6
β-strand	63-65	3	21
α-helix	69-79	11
α-helix	85-94	10
β-strand	104	1	22
α-helix	105-113	9
α-helix	121-127	7
β-strand	137	1	22
α-helix	140-149	10

Chain E: 11 helices, 6 β-strands

Element	Residues	Length	Sheet
α-helix	21-24	4
α-helix	27-39	13
β-strand	48	1	23
α-helix	50-60	11
α-helix	69-75	7
β-strand	80	1	23
α-helix	82-93	12
α-helix	99-106	8
β-strand	116-117	2	24
α-helix	119-125	7
α-helix	132-134	3
α-helix	135-139	5
α-helix	140-142	3
β-strand	148	1	25
β-strand	151	1	25
β-strand	153-154	2	24
α-helix	155-162	8

Chain F: 10 helices, 4 β-strands

Element	Residues	Length	Sheet
α-helix	16-18	3
α-helix	27-40	14
β-strand	48	1	26
α-helix	50-59	10
α-helix	67-74	8
β-strand	80	1	26
α-helix	82-92	11
α-helix	96-98	3
α-helix	99-109	11
β-strand	117	1	27
α-helix	119-126	8
α-helix	135-144	10
β-strand	151	1	27
α-helix	157-163	7

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Isoform 1 of Myosin-9	A, B	protein	1960	Homo sapiens	P35579 (AlphaFold model)
Isoform 1 of Myosin light polypeptide 6	C, D	protein	151	Gallus gallus	P02607 (AlphaFold model)
Myosin regulatory light polypeptide 9	E, F	protein	172	Bos taurus	Q5E9E2 (AlphaFold model)

Sequence of entity 1 (A, B), FASTA

>9SZR_1 Isoform 1 of Myosin-9 (chains A, B)
MAQQAADKYLYVDKNFINNPLAQADWAAKKLVWVPSDKSGFEPASLKEEVGEEAIVELVE
NGKKVKVNKDDIQKMNPPKFSKVEDMAELTCLNEASVLHNLKERYYSGLIYTYSGLFCVV
INPYKNLPIYSEEIVEMYKGKKRHEMPPHIYAITDTAYRSMMQDREDQSILCTGESGAGK
TENTKKVIQYLAYVASSHKSKKDQGELERQLLQANPILEAFGNAKTVKNDNSSRFGKFIR
INFDVNGYIVGANIETYLLEKSRAIRQAKEERTFHIFYYLLSGAGEHLKTDLLLEPYNKY
RFLSNGHVTIPGQQDKDMFQETMEAMRIMGIPEEEQMGLLRVISGVLQLGNIVFKKERNT
DQASMPDNTAAQKVSHLLGINVTDFTRGILTPRIKVGRDYVQKAQTKEQADFAIEALAKA
TYERMFRWLVLRINKALDKTKRQGASFIGILDIAGFEIFDLNSFEQLCINYTNEKLQQLF
NHTMFILEQEEYQREGIEWNFIDFGLDLQPCIDLIEKPAGPPGILALLDEECWFPKATDK
SFVEKVMQEQGTHPKFQKPKQLKDKADFCIIHYAGKVDYKADEWLMKNMDPLNDNIATLL
HQSSDKFVSELWKDVDRIIGLDQVAGMSETALPGAFKTRKGMFRTVGQLYKEQLAKLMAT
LRNTNPNFVRCIIPNHEKKAGKLDPHLVLDQLRCNGVLEGIRICRQGFPNRVVFQEFRQR
YEILTPNSIPKGFMDGKQACVLMIKALELDSNLYRIGQSKVFFRAGVLAHLEEERDLKIT
DVIIGFQACCRGYLARKAFAKRQQQLTAMKVLQRNCAAYLKLRNWQWWRLFTKVKPLLQV
SRQEEEMMAKEEELVKVREKQLAAENRLTEMETLQSQLMAEKLQLQEQLQAETELCAEAE
ELRARLTAKKQELEEICHDLEARVEEEEERCQHLQAEKKKMQQNIQELEEQLEEEESARQ
KLQLEKVTTEAKLKKLEEEQIILEDQNCKLAKEKKLLEDRIAEFTTNLTEEEEKSKSLAK
LKNKHEAMITDLEERLRREEKQRQELEKTRRKLEGDSTDLSDQIAELQAQIAELKMQLAK
KEEELQAALARVEEEAAQKNMALKKIRELESQISELQEDLESERASRNKAEKQKRDLGEE
LEALKTELEDTLDSTAAQQELRSKREQEVNILKKTLEEEAKTHEAQIQEMRQKHSQAVEE
LAEQLEQTKRVKANLEKAKQTLENERGELANEVKVLLQGKGDSEHKRKKVEAQLQELQVK
FNEGERVRTELADKVTKLQVELDNVTGLLSQSDSKSSKLTKDFSALESQLQDTQELLQEE
NRQKLSLSTKLKQVEDEKNSFREQLEEEEEAKHNLEKQIATLHAQVADMKKKMEDSVGCL
ETAEEVKRKLQKDLEGLSQRHEEKVAAYDKLEKTKTRLQQELDDLLVDLDHQRQSACNLE
KKQKKFDQLLAEEKTISAKYAEERDRAEAEAREKETKALSLARALEEAMEQKAELERLNK
QFRTEMEDLMSSKDDVGKSVHELEKSKRALEQQVEEMKTQLEELEDELQATEDAKLRLEV
NLQAMKAQFERDLQGRDEQSEEKKKQLVRQVREMEAELEDERKQRSMAVAARKKLEMDLK
DLEAHIDSANKNRDEAIKQLRKLQAQMKDCMRELDDTRASREEILAQAKENEKKLKSMEA
EMIQLQEELAAAERAKRQAQQERDELADEIANSSGKGALALEEKRRLEARIAQLEEELEE
EQGNTELINDRLKKANLQIDQINTDLNLERSHAQKNENARQQLERQNKELKVKLQEMEGT
VKSKYKASITALEAKIAQLEEQLDNETKERQAACKQVRRTEKKLKDVLLQVDDERRNAEQ
YKDQADKASTRLKQLKRQLEEAEEEAQRANASRRKLQRELEDATETADAMNREVSSLKNK
LRRGDLPFVVPRRMARKGAGDGSDEEVDGKADGAEAKPAE

Sequence of entity 2 (C, D), FASTA

>9SZR_2 Isoform 1 of Myosin light polypeptide 6 (chains C, D)
MCDFSEEQTAEFKEAFQLFDRTGDGKILYSQCGDVMRALGQNPTNAEVMKVLGNPKSDEM
NLKTLKFEQFLPMMQTIAKNKDQGCFEDYVEGLRVFDKEGNGTVMGAEIRHVLVTLGEKM
TEEEVEQLVAGHEDSNGCINYEELVRMVLSG

Sequence of entity 3 (E, F), FASTA

>9SZR_3 Myosin regulatory light polypeptide 9 (chains E, F)
MSSKRAKTKTTKKRPQRATSNVFAMFDQSQIQEFKEAFNMIDQNRDGFIDKEDLHDMLAS
LGKNPTDEYLDAMMNEAPGPINFTMFLTMFGEKLNGTDPEDVIRNAFACFDEEATGTIQE
DYLRELLTTMGDRFTDEEVDELYREAPIDKKGNFNYIEFTRILKHGAKDKDD

Ligands and cofactors

ID	Name	Formula	Copies
MG	Magnesium ion	Mg	4
PO4	Phosphate ion	O4 P	2
ADP	Adenosine-5'-diphosphate	C10 H15 N5 O10 P2	2

Primary citation

Cryo-EM structure of shutdown human nonmuscle myosin 2A. Casas-Mao, D., Carrington, G., Peckham, M. Sci Adv (2026) 12:eaed1858-eaed1858. DOI 10.1126/sciadv.aed1858 · PubMed

Other PDB entries of the same protein (UniProt P35579 (AlphaFold model), which also has an AlphaFold model), best resolution first:

4CFQ 1.37 Å, Ca-bound truncated (delta13C) and C3S, C81S and C86S mutated S100A4 complexed with…
4CFR 1.4 Å, Ca-bound S100A4 C3S, C81S, C86S and F45W mutant complexed with non- muscle myosin IIA
4ETO 1.54 Å, Structure of S100A4 in complex with non-muscle myosin-IIA peptide
3ZWH 1.94 Å, Ca2+-bound S100A4 C3S, C81S, C86S and F45W mutant complexed with myosin IIA
9IHL 2.02 Å, Crystal Structure of the Human Nonmuscle Myosin 2A Motor Domain
9SYU 2.98 Å, shutdown state non-muscle myosin 2A heads region
2LNK Solution structure of Ca-bound S100A4 in complex with non-muscle myosin IIA

Browse structure collections

About this viewer

MolViewer shows 9SZR directly in your browser with nothing to install. Switch between cartoon, ball-and-stick, spacefill and surface views, color by chain, secondary structure or B-factor, measure distances, angles and dihedrals, and share or embed the view.