Summary: Myosin head (motor domain)
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Myosin head Edit Wikipedia article
|SCOP2||1mys / SCOPe / SUPFAM|
The myosin head is the part of the thick myofilament made up of myosin that acts in muscle contraction, by sliding over thin myofilaments of actin. Myosin is the major component of the thick filaments and most myosin molecules are composed of a head, neck, and tail domain; the myosin head binds to thin filamentous actin, and uses ATP hydrolysis to generate force and "walk" along the thin filament. Myosin exists as a hexamer of two heavy chains, two alkali light chains, and two regulatory light chains. The heavy chain can be subdivided into the globular head at the N-terminal and the coiled-coil rod-like tail at the C-terminal, although some forms have a globular region in their C-terminal.
There are many cell-specific isoforms of myosin heavy chains, coded for by a multi-gene family. Myosin interacts with actin to convert chemical energy, in the form of ATP, to mechanical energy. The 3-D structure of the head portion of myosin has been determined  and a model for actin-myosin complex has been constructed.
The globular head is well conserved, and is key to contraction. Muscle contraction results from an attachmentâ€“detachment cycle between the myosin heads extending from myosin filaments and the sites on actin filaments. The myosin head first attaches to actin together with the products of ATP hydrolysis, performs a power stroke associated with release of hydrolysis products, and detaches from actin upon binding with new ATP. The detached myosin head then hydrolyses ATP, and performs a recovery stroke to restore its initial position. The strokes have been suggested to result from rotation of the lever arm domain around the converter domain, while the catalytic domain remains rigid.
- Hayashida M, Maita T, Matsuda G (July 1991). "The primary structure of skeletal muscle myosin heavy chain: I. Sequence of the amino-terminal 23 kDa fragment". J. Biochem. 110 (1): 54â€“9. doi:10.1093/oxfordjournals.jbchem.a123543. PMIDÂ 1939027.
- Eller M, Stedman HH, Sylvester JE, Fertels SH, Wu QL, Raychowdhury MK, Rubinstein NA, Kelly AM, Sarkar S (October 1989). "Human embryonic myosin heavy chain cDNA. Interspecies sequence conservation of the myosin rod, chromosomal locus and isoform specific transcription of the gene". FEBS Lett. 256 (1â€“2): 21â€“8. doi:10.1016/0014-5793(89)81710-7. PMIDÂ 2806546. S2CIDÂ 12047829.
- Warrick HM, De Lozanne A, Leinwand LA, Spudich JA (December 1986). "Conserved protein domains in a myosin heavy chain gene from Dictyostelium discoideum". Proc. Natl. Acad. Sci. U.S.A. 83 (24): 9433â€“7. Bibcode:1986PNAS...83.9433W. doi:10.1073/pnas.83.24.9433. PMCÂ 387152. PMIDÂ 3540939.
- Rayment I, Rypniewski WR, Schmidt-BÃ¤se K, Smith R, Tomchick DR, Benning MM, Winkelmann DA, Wesenberg G, Holden HM (July 1993). "Three-dimensional structure of myosin subfragment-1: a molecular motor". Science. 261 (5117): 50â€“8. Bibcode:1993Sci...261...50R. doi:10.1126/science.8316857. PMIDÂ 8316857.
- Rayment I, Holden HM, Whittaker M, Yohn CB, Lorenz M, Holmes KC, Milligan RA (July 1993). "Structure of the actin-myosin complex and its implications for muscle contraction". Science. 261 (5117): 58â€“65. Bibcode:1993Sci...261...58R. doi:10.1126/science.8316858. PMIDÂ 8316858.
- Molloy JE, Burns JE, Kendrick-Jones J, Tregear RT, White DC (November 1995). "Movement and force produced by a single myosin head". Nature. 378 (6553): 209â€“12. Bibcode:1995Natur.378..209M. doi:10.1038/378209a0. PMIDÂ 7477328. S2CIDÂ 4334476.
- Lewalle A, Steffen W, Stevenson O, Ouyang Z, Sleep J (March 2008). "Single-molecule measurement of the stiffness of the rigor myosin head". Biophysical Journal. 94 (6): 2160â€“9. Bibcode:2008BpJ....94.2160L. doi:10.1529/biophysj.107.119396. PMCÂ 2257899. PMIDÂ 18065470.
- Minoda H, Okabe T, Inayoshi Y, Miyakawa T, Miyauchi Y, Tanokura M, Katayama E, Wakabayashi T, Akimoto T, Sugi H (February 2011). "Electron microscopic evidence for the myosin head lever arm mechanism in hydrated myosin filaments using the gas environmental chamber". Biochemical and Biophysical Research Communications. 405 (4): 651â€“6. doi:10.1016/j.bbrc.2011.01.087. PMIDÂ 21281603.
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Myosin head (motor domain) Provide feedback
No Pfam abstract.
Rayment I, Holden HM, Whittaker M, Yohn CB, Lorenz M, Holmes KC, Milligan RA; , Science 1993;261:58-65.: Structure of the actin-myosin complex and its implications for muscle contraction. PUBMED:8316858 EPMC:8316858
Internal database links
|SCOOP:||AAA_16 AAA_19 AAA_22 Myosin_N Myosin_tail_1|
External database links
This tab holds annotation information from the InterPro database.
InterPro entry IPR001609
Muscle contraction is caused by sliding between the thick and thin filaments of the myofibril. Myosin is a major component of thick filaments and exists as a hexamer of 2 heavy chains [ PUBMED:1939027 ], 2 alkali light chains, and 2 regulatory light chains. The heavy chain can be subdivided into the N-terminal globular head and the C-terminal coiled-coil rod-like tail, although some forms have a globular region in their C-terminal. There are many cell-specific isoforms of myosin heavy chains, coded for by a multi-gene family [ PUBMED:2806546 ]. Myosin interacts with actin to convert chemical energy, in the form of ATP, to mechanical energy [ PUBMED:3540939 ]. The 3-D structure of the head portion of myosin has been determined [ PUBMED:8316857 ] and a model for actin-myosin complex has been constructed [ PUBMED:8316858 ].
The globular head is well conserved, some highly-conserved regions possibly relating to functional and structural domains [ PUBMED:6576334 ]. The rod-like tail starts with an invariant proline residue, and contains many repeats of a 28 residue region, interrupted at 4 regularly-spaced points known as skip residues. Although the sequence of the tail is not well conserved, the chemical character is, hydrophobic, charged and skip residues occuring in a highly ordered and repeated fashion [ PUBMED:6576334 ].
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
|Cellular component||myosin complex (GO:0016459)|
|Molecular function||ATP binding (GO:0005524)|
|motor activity (GO:0003774)|
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The clan contains the following 245 members:6PF2K AAA AAA-ATPase_like AAA_10 AAA_11 AAA_12 AAA_13 AAA_14 AAA_15 AAA_16 AAA_17 AAA_18 AAA_19 AAA_2 AAA_21 AAA_22 AAA_23 AAA_24 AAA_25 AAA_26 AAA_27 AAA_28 AAA_29 AAA_3 AAA_30 AAA_31 AAA_32 AAA_33 AAA_34 AAA_35 AAA_5 AAA_6 AAA_7 AAA_8 AAA_9 AAA_PrkA ABC_ATPase ABC_tran ABC_tran_Xtn Adeno_IVa2 Adenylsucc_synt ADK AFG1_ATPase AIG1 APS_kinase Arf ArsA_ATPase ATP-synt_ab ATP_bind_1 ATP_bind_2 ATPase ATPase_2 Bac_DnaA BCA_ABC_TP_C Beta-Casp bpMoxR BrxC_BrxD BrxL_ATPase Cas_Csn2 Cas_St_Csn2 CbiA CBP_BcsQ CDC73_C CENP-M CFTR_R CLP1_P CMS1 CoaE CobA_CobO_BtuR CobU cobW CPT CSM2 CTP_synth_N Cytidylate_kin Cytidylate_kin2 DAP3 DEAD DEAD_2 divDNAB DLIC DNA_pack_C DNA_pack_N DNA_pol3_delta DNA_pol3_delta2 DnaB_C dNK DO-GTPase1 DO-GTPase2 DUF1611 DUF2075 DUF2326 DUF2478 DUF257 DUF2813 DUF3584 DUF463 DUF4914 DUF5906 DUF6079 DUF815 DUF835 DUF87 DUF927 Dynamin_N Dynein_heavy Elong_Iki1 ELP6 ERCC3_RAD25_C Exonuc_V_gamma FeoB_N Fer4_NifH Flavi_DEAD FTHFS FtsK_SpoIIIE G-alpha Gal-3-0_sulfotr GBP GBP_C GpA_ATPase GpA_nuclease GTP_EFTU Gtr1_RagA Guanylate_kin GvpD_P-loop HDA2-3 Helicase_C Helicase_C_2 Helicase_C_4 Helicase_RecD HerA_C Herpes_Helicase Herpes_ori_bp Herpes_TK HydF_dimer HydF_tetramer Hydin_ADK IIGP IPPT IPT iSTAND IstB_IS21 KAP_NTPase KdpD Kinase-PPPase Kinesin KTI12 LAP1_C LpxK MCM MeaB MEDS Mg_chelatase Microtub_bd MipZ MMR_HSR1 MMR_HSR1_C MobB MukB Mur_ligase_M MutS_V Myosin_head NACHT NAT_N NB-ARC NOG1 NTPase_1 NTPase_P4 ORC3_N P-loop_TraG ParA Parvo_NS1 PAXNEB PduV-EutP PhoH PIF1 Ploopntkinase1 Ploopntkinase2 Ploopntkinase3 Podovirus_Gp16 Polyoma_lg_T_C Pox_A32 PPK2 PPV_E1_C PRK PSY3 Rad17 Rad51 Ras RecA ResIII RHD3_GTPase RhoGAP_pG1_pG2 RHSP RNA12 RNA_helicase Roc RsgA_GTPase RuvB_N SbcC_Walker_B SecA_DEAD Senescence Septin Sigma54_activ_2 Sigma54_activat SKI SMC_N SNF2-rel_dom SpoIVA_ATPase Spore_III_AA SRP54 SRPRB SulA Sulfotransfer_1 Sulfotransfer_2 Sulfotransfer_3 Sulfotransfer_4 Sulfotransfer_5 Sulphotransf SWI2_SNF2 T2SSE T4SS-DNA_transf TerL_ATPase Terminase_3 Terminase_6N Thymidylate_kin TIP49 TK TmcA_N TniB Torsin TraG-D_C tRNA_lig_kinase TrwB_AAD_bind TsaE UvrB UvrD-helicase UvrD_C UvrD_C_2 Viral_helicase1 VirC1 VirE YqeC Zeta_toxin Zot
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|Seed source:||Blastp MYSA_HUMAN/1-840|
|Number in seed:||16|
|Number in full:||47835|
|Average length of the domain:||505.60 aa|
|Average identity of full alignment:||31 %|
|Average coverage of the sequence by the domain:||40.80 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 61295632 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||24|
|Download:||download the raw HMM for this family|
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For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the Myosin_head domain has been found. There are 306 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein sequence.
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AlphaFold Structure Predictions
The list of proteins below match this family and have AlphaFold predicted structures. Click on the protein accession to view the predicted structure.