ID   CM3B_CONPI              Reviewed;          22 AA.
AC   P0CH16;
DT   10-AUG-2010, integrated into UniProtKB/Swiss-Prot.
DT   10-AUG-2010, sequence version 1.
DT   25-MAY-2022, entry version 24.
DE   RecName: Full=Mu-conotoxin-like pr3b;
OS   Conus parius (Cone snail).
OC   Eukaryota; Metazoa; Spiralia; Lophotrochozoa; Mollusca; Gastropoda;
OC   Caenogastropoda; Neogastropoda; Conoidea; Conidae; Conus; Phasmoconus.
OX   NCBI_TaxID=505247;
RN   [1]
RP   PROTEIN SEQUENCE, NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, HYDROXYLATION AT
RP   PRO-8 AND PRO-18, AMIDATION AT CYS-22, AND MASS SPECTROMETRY.
RC   TISSUE=Venom, and Venom duct;
RX   PubMed=20570703; DOI=10.1016/j.peptides.2010.05.020;
RA   Jimenez E.C., Olivera B.M.;
RT   "Divergent M- and O-superfamily peptides from venom of fish-hunting Conus
RT   parius.";
RL   Peptides 31:1678-1683(2010).
CC   -!- FUNCTION: Mu-conotoxins block voltage-gated sodium channels (Nav) (By
CC       similarity). Intraperitoneal injection into fish (1 nmol) provokes
CC       weakening and difficulty in swimming after 20 min. {ECO:0000250,
CC       ECO:0000269|PubMed:20570703}.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom duct.
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.
CC   -!- MASS SPECTROMETRY: Mass=2500.1; Method=MALDI; Note=Monoisotopic mass.;
CC       Evidence={ECO:0000269|PubMed:20570703};
CC   -!- MISCELLANEOUS: Authors confirmed the assignment of this toxin to the M
CC       superfamily by cDNA sequencing.
CC   -!- SIMILARITY: Belongs to the conotoxin M superfamily. {ECO:0000305}.
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DR   AlphaFoldDB; P0CH16; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0019871; F:sodium channel inhibitor activity; IEA:InterPro.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   InterPro; IPR008036; Conotoxin_mu-typ.
DR   Pfam; PF05374; Mu-conotoxin; 1.
PE   1: Evidence at protein level;
KW   Amidation; Direct protein sequencing; Disulfide bond; Hydroxylation;
KW   Ion channel impairing toxin; Neurotoxin; Secreted; Toxin;
KW   Voltage-gated sodium channel impairing toxin.
FT   PEPTIDE         1..22
FT                   /note="Mu-conotoxin-like pr3b"
FT                   /id="PRO_0000397114"
FT   MOD_RES         8
FT                   /note="4-hydroxyproline"
FT                   /evidence="ECO:0000269|PubMed:20570703"
FT   MOD_RES         18
FT                   /note="4-hydroxyproline"
FT                   /evidence="ECO:0000269|PubMed:20570703"
FT   MOD_RES         22
FT                   /note="Cysteine amide"
FT                   /evidence="ECO:0000269|PubMed:20570703"
FT   DISULFID        4..16
FT                   /evidence="ECO:0000250|UniProtKB:P01523"
FT   DISULFID        5..21
FT                   /evidence="ECO:0000250|UniProtKB:P01523"
FT   DISULFID        11..22
FT                   /evidence="ECO:0000250|UniProtKB:P01523"
SQ   SEQUENCE   22 AA;  2475 MW;  E43AB9FE266EC853 CRC64;
     ERVCCGYPMS CKSRACKPSY CC