ID   CA1A_CONST              Reviewed;          13 AA.
AC   P28878;
DT   01-DEC-1992, integrated into UniProtKB/Swiss-Prot.
DT   01-DEC-1992, sequence version 1.
DT   23-FEB-2022, entry version 71.
DE   RecName: Full=Alpha-conotoxin SIA;
DE   AltName: Full=S1A;
OS   Conus striatus (Striated cone).
OC   Eukaryota; Metazoa; Spiralia; Lophotrochozoa; Mollusca; Gastropoda;
OC   Caenogastropoda; Neogastropoda; Conoidea; Conidae; Conus; Pionoconus.
OX   NCBI_TaxID=6493;
RN   [1]
RP   PROTEIN SEQUENCE, AND AMIDATION AT CYS-13.
RC   TISSUE=Venom;
RX   PubMed=1892838; DOI=10.1021/bi00102a034;
RA   Myers R.A., Zafarella G.C., Gray W.R., Abbot J., Cruz L.J., Olivera B.M.;
RT   "Alpha-conotoxins, small peptide probes of nicotinic acetylcholine
RT   receptors.";
RL   Biochemistry 30:9370-9377(1991).
CC   -!- FUNCTION: Alpha-conotoxins act on postsynaptic membranes, they bind to
CC       the nicotinic acetylcholine receptors (nAChR) and thus inhibit them.
CC       This toxin blocks muscular nAChR alpha-1/gamma subunits.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom duct.
CC   -!- DOMAIN: The cysteine framework is I (CC-C-C). Alpha3/5 pattern.
CC   -!- SIMILARITY: Belongs to the conotoxin A superfamily. {ECO:0000305}.
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DR   PIR; A40312; NTKNAS.
DR   ConoServer; 25; SIA.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0035792; C:host cell postsynaptic membrane; IEA:UniProtKB-KW.
DR   GO; GO:0030550; F:acetylcholine receptor inhibitor activity; IEA:UniProtKB-KW.
DR   GO; GO:0099106; F:ion channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   InterPro; IPR018072; Conotoxin_a-typ_CS.
DR   PROSITE; PS60014; ALPHA_CONOTOXIN; 1.
PE   1: Evidence at protein level;
KW   Acetylcholine receptor inhibiting toxin; Amidation;
KW   Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW   Neurotoxin; Postsynaptic neurotoxin; Secreted; Toxin.
FT   PEPTIDE         1..13
FT                   /note="Alpha-conotoxin SIA"
FT                   /id="PRO_0000044463"
FT   MOD_RES         13
FT                   /note="Cysteine amide"
FT                   /evidence="ECO:0000269|PubMed:1892838"
FT   DISULFID        2..7
FT                   /evidence="ECO:0000250|UniProtKB:P01519"
FT   DISULFID        3..13
FT                   /evidence="ECO:0000250|UniProtKB:P01519"
SQ   SEQUENCE   13 AA;  1461 MW;  DEF1931982457EBD CRC64;
     YCCHPACGKN FDC