ID   MLRA_MIZYE              Reviewed;         161 AA.
AC   P04113;
DT   01-NOV-1986, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1986, sequence version 1.
DT   03-AUG-2022, entry version 91.
DE   RecName: Full=Myosin regulatory light chain A, smooth adductor muscle;
OS   Mizuhopecten yessoensis (Japanese scallop) (Patinopecten yessoensis).
OC   Eukaryota; Metazoa; Spiralia; Lophotrochozoa; Mollusca; Bivalvia;
OC   Autobranchia; Pteriomorphia; Pectinida; Pectinoidea; Pectinidae;
OC   Mizuhopecten.
OX   NCBI_TaxID=6573;
RN   [1]
RP   PROTEIN SEQUENCE.
RX   PubMed=4008467; DOI=10.1093/oxfordjournals.jbchem.a135089;
RA   Miyanishi T., Maita T., Morita F., Kondo S., Matsuda G.;
RT   "Amino acid sequences of the two kinds of regulatory light chains of
RT   adductor smooth muscle myosin from Patinopecten yessoensis.";
RL   J. Biochem. 97:541-551(1985).
RN   [2]
RP   CALCIUM-BINDING DATA.
RX   PubMed=4008468; DOI=10.1093/oxfordjournals.jbchem.a135090;
RA   Morita F., Kondo S., Tomari K., Minova O., Ikura M., Hikichi K.;
RT   "Calcium binding and conformation of regulatory light chains of smooth
RT   muscle myosin of scallop.";
RL   J. Biochem. 97:553-561(1985).
CC   -!- FUNCTION: In molluscan muscle, calcium regulation is associated with
CC       myosin rather than with actin. Muscle myosin contains two types of
CC       light chains: the catalytic light chain, essential for ATPase activity,
CC       and the regulatory light chain, a calcium-binding protein responsible
CC       for Ca(2+) dependent binding and Ca(2+) dependent Mg-ATPase activity.
CC   -!- MISCELLANEOUS: Smooth muscle myosin from the scallop adductor muscle
CC       contains two kinds of RLC proteins, A and B. Because RLCA hydrolyzes
CC       ATP and superprecipitates more slowly than RLCB, myosins containing
CC       RLCA are thought to induce the catch mechanism, a tonic contraction
CC       characterizing smooth muscle that is maintained with very slow ATP
CC       hydrolysis.
CC   -!- MISCELLANEOUS: The calcium affinity of the smooth muscle RLC is
CC       approximately 10 times that of the RLC of striated muscle.
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DR   PIR; A03048; MOSWLA.
DR   AlphaFoldDB; P04113; -.
DR   SMR; P04113; -.
DR   GO; GO:0016459; C:myosin complex; IEA:UniProtKB-KW.
DR   GO; GO:0005509; F:calcium ion binding; IEA:InterPro.
DR   InterPro; IPR011992; EF-hand-dom_pair.
DR   InterPro; IPR018247; EF_Hand_1_Ca_BS.
DR   InterPro; IPR002048; EF_hand_dom.
DR   Pfam; PF13405; EF-hand_6; 1.
DR   SMART; SM00054; EFh; 2.
DR   SUPFAM; SSF47473; SSF47473; 1.
DR   PROSITE; PS00018; EF_HAND_1; 1.
DR   PROSITE; PS50222; EF_HAND_2; 2.
PE   1: Evidence at protein level;
KW   Calcium; Direct protein sequencing; Metal-binding; Motor protein;
KW   Muscle protein; Myosin; Repeat.
FT   CHAIN           1..161
FT                   /note="Myosin regulatory light chain A, smooth adductor
FT                   muscle"
FT                   /id="PRO_0000198755"
FT   DOMAIN          20..55
FT                   /note="EF-hand 1"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00448"
FT   DOMAIN          89..124
FT                   /note="EF-hand 2"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00448"
FT   BINDING         33
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00448"
FT   BINDING         35
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00448"
FT   BINDING         37
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00448"
FT   BINDING         44
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00448"
FT   MOD_RES         1
FT                   /note="Blocked amino end (Ala)"
FT                   /evidence="ECO:0000269|PubMed:4008467"
SQ   SEQUENCE   161 AA;  18384 MW;  658525E98AD11B44 CRC64;
     ADKERAQRAT SNVFARLPQK LMQEMKEAFT MIDQNRDGFI DINDLKEMFS SLGRTPDDKE
     LTAMLKEAPG PLNFTMFLSI FSDKLSGTDT EETLRNAFAM FDELDTKKLN IEYIKDLLEN
     MGDNFTKDEM RMTFKEAPVT GGKFDYVKFT AMIKGSGEEE A