1SR6: Nucleotide-free scallop myosin S1

Structure of nucleotide-free scallop myosin S1. Determined by X-ray diffraction at 2.75 Å resolution. Released 15 Jun 2004.

Method: X-ray diffraction
Resolution: 2.75 Å
Organism: Argopecten irradians
Chains: 3
Atoms: 8,895
Mol. weight: 131.17 kDa
Ligands: CA, MG
Released: 15 Jun 2004

Explore 1SR6 in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

1SR6 contains 55 α-helices and 32 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: 37 helices, 25 β-strands

Element	Residues	Length	Sheet
α-helix	8-10	3
α-helix	17-21	5
β-strand	33-38	6	1
β-strand	42-51	10	1
β-strand	55-59	5	1
β-strand	67-70	4	1
β-strand	75-76	2	1
α-helix	80-82	3
β-strand	87	1	2
α-helix	96-108	13
β-strand	113-116	4	2
β-strand	119-123	5	2
α-helix	130-132	3
α-helix	134-140	7
α-helix	145-147	3
α-helix	152-162	11
α-helix	163-167	5
β-strand	170-175	6	2
α-helix	182-193	12
α-helix	215-230	16
β-strand	231-232	2	3
β-strand	240-241	2	3
β-strand	244-251	8	2
β-strand	257-265	9	2
α-helix	269-273	5
α-helix	283-288	6
α-helix	294-296	3
α-helix	297-300	4
α-helix	306-308	3
α-helix	324-338	15
α-helix	342-358	17
β-strand	363-364	2	4
β-strand	373-374	2	4
α-helix	378-386	9
α-helix	391-398	8
α-helix	416-446	31
β-strand	454-460	7	2
β-strand	470	1	5
α-helix	472-502	31
α-helix	515-524	10
α-helix	529-535	7
α-helix	544-555	12
β-strand	562-563	2	5
β-strand	578-582	5	5
β-strand	585-589	5	5
α-helix	594-598	5
α-helix	604-611	8
α-helix	616-621	6
α-helix	645-660	16
β-strand	664	1	2
β-strand	667-671	5	2
α-helix	684-694	11
α-helix	696-704	9
β-strand	710-711	2	6
α-helix	713-720	8
α-helix	721-723	3
α-helix	725-727	3
α-helix	736-745	10
β-strand	753-755	3	6
β-strand	760-762	3	6
α-helix	766-821	56
α-helix	825-831	7

Chain B: 7 helices, 3 β-strands

Element	Residues	Length	Sheet
α-helix	16-21	6
α-helix	41-44	4
α-helix	86-89	4
α-helix	93-95	3
β-strand	104-105	2	7
α-helix	106-115	10
α-helix	122-128	7
β-strand	134-135	2	7
β-strand	138-139	2	7
α-helix	141-149	9

Chain C: 11 helices, 4 β-strands

Element	Residues	Length	Sheet
α-helix	2-4	3
α-helix	5-20	16
β-strand	28-29	2	8
α-helix	30-32	3
α-helix	33-38	6
α-helix	46-50	5
β-strand	62-63	2	8
α-helix	65-67	3
α-helix	68-75	8
α-helix	83-91	9
β-strand	100-102	3	9
α-helix	103-112	10
α-helix	119-129	11
β-strand	138-140	3	9
α-helix	141-150	10

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Myosin heavy chain, striated muscle	A	protein	840	Argopecten irradians	P24733 (AlphaFold model)
Myosin regulatory light chain, striated adductor muscle	B	protein	156	Argopecten irradians	P13543 (AlphaFold model)
Myosin essential light chain, striated adductor muscle	C	protein	156	Argopecten irradians	P07291 (AlphaFold model)

Sequence of entity 1 (A), FASTA

>1SR6_1 Myosin heavy chain, striated muscle (chains A)
MNIDFSDPDFQYLAVDRKKLMKEQTAAFDGKKNCWVPDEKEGFASAEIQSSKGDEITVKI
VADSSTRTVKKDDIQSMNPPKFEKLEDMANMTYLNEASVLYNLRSRYTSGLIYTYSGLFC
IAVNPYRRLPIYTDSVIAKYRGKRKTEIPPHLFSVADNAYQNMVTDRENQSCLITGESGA
GKTENTKKVIMYLAKVACAVKKKDEEASDKKEGSLEDQIIQANPVLEAYGNAKTTRNNNS
SRFGKFIRIHFGPTGKIAGADIETYLLEKSRVTYQQSAERNYHIFYQICSNAIPELNDVM
LVTPDSGLYSFINQGCLTVDNIDDVEEFKLCDEAFDILGFTKEEKQSMFKCTASILHMGE
MKFKQRPREEQAESDGTAEAEKVAFLCGINAGDLLKALLKPKVKVGTEMVTKGQNMNQVV
NSVGALAKSLYDRMFNWLVRRVNKTLDTKAKRNYYIGVLDIAGFEIFDFNSFEQLCINYT
NERLQQFFNHHMFILEQEEYKKEGIAWEFIDFGMDLQMCIDLIEKPMGILSILEEECMFP
KADDKSFQDKLYQNHMGKNRMFTKPGKPTRPNQGPAHFELHHYAGNVPYSITGWLEKNKD
PINENVVALLGASKEPLVAELFKAPEEPAGGGKKKKGKSSAFQTISAVHRESLNKLMKNL
YSTHPHFVRCIIPNELKQPGLVDAELVLHQLQCNGVLEGIRICRKGFPSRLIYSEFKQRY
SILAPNAIPQGFVDGKTVSEKILAGLQMDPAEYRLGTTKVFFKAGVLGNLEEMRDERLSK
IISMFQAHIRGYLIRKAYKKLQDQRIGLSVIQRNIRKWLVLRNWQWWKLYSKVKPLLSIA

Sequence of entity 2 (B), FASTA

>1SR6_2 Myosin regulatory light chain, striated adductor muscle (chains B)
ADKAASGVLTKLPQKQIQEMKEAFSMIDVDRDGFVSKEDIKAISEQLGRAPDDKELTAML
KEAPGPLNFTMFLSIFSDKLSGTDSEETIRNAFAMFDEQETKKLNIEYIKDLLENMGDNF
NKDEMRMTFKEAPVEGGKFDYVKFTAMIKGSGEEEA

Sequence of entity 3 (C), FASTA

>1SR6_3 Myosin essential light chain, striated adductor muscle (chains C)
PKLSQDEIDDLKDVFELFDFWDGRDGAVDAFKLGDVCRCLGINPRNEDVFAVGGTHKMGE
KSLPFEEFLPAYEGLMDCEQGTFADYMEAFKTFDREGQGFISGAELRHVLTALGERLSDE
DVDEIIKLTDLQEDLEGNVKYEDFVKKVMAGPYPDK

Ligands and cofactors

ID	Name	Formula	Copies
CA	Calcium ion	Ca	1
MG	Magnesium ion	Mg	1

Water and common crystallization additives (SO4) are not listed.

Primary citation

Myosin subfragment 1 structures reveal a partially bound nucleotide and a complex salt bridge that helps couple nucleotide and actin binding. Risal, D., Gourinath, S., Himmel, D.M. et al. Proc Natl Acad Sci U S A (2004) 101:8930-8935. DOI 10.1073/pnas.0403002101 · PubMed

Other PDB entries of the same protein (UniProt P24733 (AlphaFold model), which also has an AlphaFold model), best resolution first:

1WDC 2.0 Å, Scallop myosin regulatory domain
3JVT 2.1 Å, Calcium-bound Scallop Myosin Regulatory Domain (Lever Arm) with Reconstituted Complete…
1KK8 2.3 Å, Scallop myosin (S1-ADP-befx) in the actin-detached conformation
3BAS 2.3 Å, Crystal structure of the N-terminal region of the scallop myosin rod, monoclinic (C2) form
3BAT 2.3 Å, Crystal structure of the N-terminal region of the scallop myosin rod, monoclinic (P21)…
1B7T 2.5 Å, Myosin digested by papain
1QVI 2.54 Å, Crystal structure of scallop myosin S1 in the pre-power stroke state to 2.6 Angstrom…
3JTD 2.57 Å, Calcium-free Scallop Myosin Regulatory Domain with ELC-D19A Point Mutation
1L2O 2.8 Å, Scallop myosin S1-ADP-p-pdm in the actin-detached conformation
1SCM 2.8 Å, Structure of the regulatory domain of scallop myosin at 2.8 Å resolution
1KQM 3.0 Å, Scallop myosin S1-amppnp in the actin-detached conformation
1S5G 3.1 Å, Structure of Scallop myosin S1 reveals a novel nucleotide conformation

Browse structure collections

About this viewer

MolViewer shows 1SR6 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.