ID   CM3B_CONSR              Reviewed;          23 AA.
AC   P0C8V3;
DT   03-MAR-2009, integrated into UniProtKB/Swiss-Prot.
DT   03-MAR-2009, sequence version 1.
DT   25-MAY-2022, entry version 29.
DE   RecName: Full=Mu-conotoxin-like SxIIIB {ECO:0000303|PubMed:18831583};
OS   Conus striolatus (Cone snail).
OC   Eukaryota; Metazoa; Spiralia; Lophotrochozoa; Mollusca; Gastropoda;
OC   Caenogastropoda; Neogastropoda; Conoidea; Conidae; Conus; Pionoconus.
OX   NCBI_TaxID=101315;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], PYROGLUTAMATE FORMATION AT GLN-1, AND AMIDATION
RP   AT ALA-23.
RC   TISSUE=Venom duct;
RX   PubMed=18831583; DOI=10.1021/ja804303p;
RA   Walewska A., Skalicky J.J., Davis D.R., Zhang M.-M., Lopez-Vera E.,
RA   Watkins M., Han T.S., Yoshikami D., Olivera B.M., Bulaj G.;
RT   "NMR-based mapping of disulfide bridges in cysteine-rich peptides:
RT   application to the mu-conotoxin SxIIIA.";
RL   J. Am. Chem. Soc. 130:14280-14286(2008).
CC   -!- FUNCTION: Mu-conotoxins block voltage-gated sodium channels (Nav).
CC       {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000305|PubMed:18831583}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom duct.
CC       {ECO:0000305|PubMed:18831583}.
CC   -!- DOMAIN: The cysteine framework is III (CC-C-C-CC). Classified in the M-
CC       4 branch, since 4 residues stand between the fourth and the fifth
CC       cysteine residues. {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the conotoxin M superfamily. {ECO:0000305}.
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DR   AlphaFoldDB; P0C8V3; -.
DR   ConoServer; 3585; SxIIIB.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0017080; F:sodium channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
PE   1: Evidence at protein level;
KW   Amidation; Disulfide bond; Ion channel impairing toxin; Neurotoxin;
KW   Pyrrolidone carboxylic acid; Secreted; Toxin;
KW   Voltage-gated sodium channel impairing toxin.
FT   PEPTIDE         1..23
FT                   /note="Mu-conotoxin-like SxIIIB"
FT                   /evidence="ECO:0000305|PubMed:18831583"
FT                   /id="PRO_0000366073"
FT   MOD_RES         1
FT                   /note="Pyrrolidone carboxylic acid"
FT                   /evidence="ECO:0000305|PubMed:18831583"
FT   MOD_RES         23
FT                   /note="Alanine amide"
FT                   /evidence="ECO:0000305|PubMed:18831583"
FT   DISULFID        3..16
FT                   /evidence="ECO:0000250|UniProtKB:P01523,
FT                   ECO:0000305|PubMed:18831583"
FT   DISULFID        4..21
FT                   /evidence="ECO:0000250|UniProtKB:P01523,
FT                   ECO:0000305|PubMed:18831583"
FT   DISULFID        11..22
FT                   /evidence="ECO:0000250|UniProtKB:P01523,
FT                   ECO:0000305|PubMed:18831583"
SQ   SEQUENCE   23 AA;  2406 MW;  4395D35B8FB65B5D CRC64;
     QKCCTGKKGS CSGRACKNLR CCA