ID   MLR_HALRO               Reviewed;         153 AA.
AC   P07461;
DT   01-APR-1988, integrated into UniProtKB/Swiss-Prot.
DT   01-APR-1988, sequence version 1.
DT   03-AUG-2022, entry version 81.
DE   RecName: Full=Myosin regulatory light chain, smooth muscle;
OS   Halocynthia roretzi (Sea squirt) (Cynthia roretzi).
OC   Eukaryota; Metazoa; Chordata; Tunicata; Ascidiacea; Stolidobranchia;
OC   Pyuridae; Halocynthia.
OX   NCBI_TaxID=7729;
RN   [1]
RP   PROTEIN SEQUENCE.
RA   Takagi T., Kudoh S., Konishi K.;
RT   "The amino acid sequence of ascidian (Halocynthia roretzi) myosin light
RT   chains.";
RL   Biochim. Biophys. Acta 874:318-325(1986).
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.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   PIR; A26092; A26092.
DR   AlphaFoldDB; P07461; -.
DR   SMR; P07461; -.
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; 3.
PE   1: Evidence at protein level;
KW   Calcium; Direct protein sequencing; Metal-binding; Motor protein;
KW   Muscle protein; Myosin; Repeat.
FT   CHAIN           1..153
FT                   /note="Myosin regulatory light chain, smooth muscle"
FT                   /id="PRO_0000198748"
FT   DOMAIN          12..47
FT                   /note="EF-hand 1"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00448"
FT   DOMAIN          81..116
FT                   /note="EF-hand 2"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00448"
FT   DOMAIN          117..152
FT                   /note="EF-hand 3"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00448"
FT   BINDING         25
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00448"
FT   BINDING         27
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00448"
FT   BINDING         29
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00448"
FT   BINDING         36
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00448"
SQ   SEQUENCE   153 AA;  17272 MW;  EA89BBB926A7595A CRC64;
     ATSNVFSMFD QSQIQEFKEA FTMIDANRDG FIDQEDLKDT YASLGRGIKD ERIRDMLAES
     SGPVNFQIFL GLFGDKLSGT DPEETILEAF KILDADNKGV INKNYLAEIM MTQADRFSQS
     EVNQMFDISP IDVAGNLDYK SLCYIITHGQ EEE