ID   CA4A_CONST              Reviewed;          69 AA.
AC   P0C828; P58921; Q8I6N6;
DT   22-JUL-2008, integrated into UniProtKB/Swiss-Prot.
DT   22-JUL-2008, sequence version 1.
DT   25-MAY-2022, entry version 37.
DE   RecName: Full=Kappa-conotoxin SIVA;
DE   AltName: Full=Kappa-A-conotoxin S4.1;
DE   AltName: Full=Spastic peptide;
DE   Flags: Precursor;
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   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Venom duct;
RX   PubMed=14602116; DOI=10.1016/j.toxicon.2003.08.005;
RA   Wang C.-Z., Jiang H., Ou Z.-L., Chen J.-S., Chi C.-W.;
RT   "cDNA cloning of two A-superfamily conotoxins from Conus striatus.";
RL   Toxicon 42:613-619(2003).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   STRAIN=Isolate Philippines; TISSUE=Venom duct;
RX   PubMed=14701840; DOI=10.1074/jbc.m309654200;
RA   Santos A.D., McIntosh J.M., Hillyard D.R., Cruz L.J., Olivera B.M.;
RT   "The A-superfamily of conotoxins: structural and functional divergence.";
RL   J. Biol. Chem. 279:17596-17606(2004).
RN   [3]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Venom duct;
RX   PubMed=16183187; DOI=10.1016/j.biochi.2005.08.001;
RA   Pi C., Liu Y., Peng C., Jiang X., Liu J., Xu B., Yu X., Yu Y., Jiang X.,
RA   Wang L., Dong M., Chen S., Xu A.-L.;
RT   "Analysis of expressed sequence tags from the venom ducts of Conus
RT   striatus: focusing on the expression profile of conotoxins.";
RL   Biochimie 88:131-140(2006).
RN   [4]
RP   PROTEIN SEQUENCE OF 39-68, FUNCTION, GLYCOSYLATION AT SER-45, PYROGLUTAMATE
RP   FORMATION AT GLN-39, AMIDATION AT CYS-68, AND MASS SPECTROMETRY.
RC   TISSUE=Venom;
RX   PubMed=9819194; DOI=10.1021/bi981690a;
RA   Craig A.G., Zafaralla G.C., Cruz L.J., Santos A.D., Hillyard D.R.,
RA   Dykert J., Rivier J.E., Gray W.R., Imperial J.S., DelaCruz R.G.,
RA   Sporning A., Terlau H., West P.J., Yoshikami D., Olivera B.M.;
RT   "An O-glycosylated neuroexcitatory conus peptide.";
RL   Biochemistry 37:16019-16025(1998).
CC   -!- FUNCTION: Kappa-conotoxins bind and inhibit voltage-gated potassium
CC       channels. When injected intraperitoneally in fish, SIVA induces a
CC       period of rapid swimming followed by a spastic paralysis with stiff
CC       fibrillating fins. At high doses, the peptide is lethal to both fish
CC       and mice. {ECO:0000269|PubMed:9819194}.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom duct.
CC   -!- DOMAIN: The cysteine framework is IV (CC-C-C-C-C).
CC   -!- PTM: Contains 3 disulfide bonds (By similarity). They are not added,
CC       since framework IV presents two different connectivities (I-V, II-III,
CC       IV-VI and I-III, II-V, IV-VI). {ECO:0000250}.
CC   -!- PTM: O-linked glycan consists of Hex3-HexNAc2 pentasaccharide.
CC       {ECO:0000305|PubMed:9819194}.
CC   -!- MASS SPECTROMETRY: Mass=4084.2; Method=LSI;
CC       Evidence={ECO:0000269|PubMed:9819194};
CC   -!- SIMILARITY: Belongs to the conotoxin A superfamily. {ECO:0000305}.
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DR   EMBL; AY166873; AAN86573.1; -; mRNA.
DR   AlphaFoldDB; P0C828; -.
DR   SMR; P0C828; -.
DR   iPTMnet; P0C828; -.
DR   ConoServer; 94; SIVA precursor.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0030550; F:acetylcholine receptor inhibitor activity; IEA:InterPro.
DR   GO; GO:0015459; F:potassium channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   InterPro; IPR009958; Conotoxin_a-typ.
DR   Pfam; PF07365; Toxin_8; 1.
PE   1: Evidence at protein level;
KW   Amidation; Direct protein sequencing; Disulfide bond; Glycoprotein;
KW   Hydroxylation; Ion channel impairing toxin; Neurotoxin;
KW   Potassium channel impairing toxin; Pyrrolidone carboxylic acid; Secreted;
KW   Signal; Toxin.
FT   SIGNAL          1..21
FT                   /evidence="ECO:0000255"
FT   PROPEP          22..38
FT                   /evidence="ECO:0000269|PubMed:9819194"
FT                   /id="PRO_0000034983"
FT   PEPTIDE         39..68
FT                   /note="Kappa-conotoxin SIVA"
FT                   /id="PRO_0000034984"
FT   MOD_RES         39
FT                   /note="Pyrrolidone carboxylic acid"
FT                   /evidence="ECO:0000269|PubMed:9819194"
FT   MOD_RES         55
FT                   /note="4-hydroxyproline"
FT                   /evidence="ECO:0000250"
FT   MOD_RES         60
FT                   /note="4-hydroxyproline"
FT                   /evidence="ECO:0000250"
FT   MOD_RES         61
FT                   /note="4-hydroxyproline"
FT                   /evidence="ECO:0000250"
FT   MOD_RES         68
FT                   /note="Cysteine amide"
FT                   /evidence="ECO:0000269|PubMed:9819194"
FT   CARBOHYD        45
FT                   /note="O-linked (HexNAc...) serine"
FT                   /evidence="ECO:0000269|PubMed:9819194"
FT   CONFLICT        2
FT                   /note="G -> D (in Ref. 3)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        18
FT                   /note="T -> N (in Ref. 3)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        44
FT                   /note="P -> H (in Ref. 3)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   69 AA;  7373 MW;  1485FD154E51FF3A CRC64;
     MGMRMMFTVF LLVVLATTVV STPSDRASDG RNAAVHERQK SLVPSVITTC CGYDPGTMCP
     PCRCTNSCG