ID   MLR_SPISA               Reviewed;         160 AA.
AC   P08051;
DT   01-AUG-1988, integrated into UniProtKB/Swiss-Prot.
DT   01-AUG-1988, sequence version 1.
DT   03-AUG-2022, entry version 86.
DE   RecName: Full=Myosin regulatory light chain, smooth muscle;
OS   Spisula sachalinensis (Sakhalin surf-clam) (Pseudocardium sachalinense).
OC   Eukaryota; Metazoa; Spiralia; Lophotrochozoa; Mollusca; Bivalvia;
OC   Autobranchia; Heteroconchia; Euheterodonta; Imparidentia; Neoheterodontei;
OC   Venerida; Mactroidea; Mactridae; Pseudocardium.
OX   NCBI_TaxID=81899;
RN   [1]
RP   PROTEIN SEQUENCE.
RX   PubMed=3392003; DOI=10.1093/oxfordjournals.jbchem.a122308;
RA   Tanaka H., Maita T., Ojima T., Nishita K., Matsuda G.;
RT   "Amino acid sequence of the regulatory light chain of clam foot muscle
RT   myosin.";
RL   J. Biochem. 103:572-580(1988).
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: This chain binds calcium.
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DR   PIR; A41455; A41455.
DR   AlphaFoldDB; P08051; -.
DR   SMR; P08051; -.
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   Pfam; PF13499; EF-hand_7; 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; Phosphoprotein; Repeat.
FT   CHAIN           1..160
FT                   /note="Myosin regulatory light chain, smooth muscle"
FT                   /id="PRO_0000198749"
FT   DOMAIN          20..55
FT                   /note="EF-hand 1"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00448"
FT   DOMAIN          88..123
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 (Ser)"
FT   MOD_RES         11
FT                   /note="Phosphoserine"
FT                   /evidence="ECO:0000255"
SQ   SEQUENCE   160 AA;  17994 MW;  0B8EA14CAA3F7534 CRC64;
     SDDKKAKAAT SSVLTKFTQN QIQEMKEAFT MIDQNRDGLI DVSDLKEMYS NLGTAPQDSV
     LQAMVKEAPQ MNFTGFLSLF SEKMSGTDPE ETLRNAFQMF DSDNTGYIPE EYMKDLLENM
     GDNFSKDEVR QTWKEAPIAG GKVDYNAFVS KIKGKEQDDA