ID   CXAT5_CONMS             Reviewed;          95 AA.
AC   P0CE30;
DT   02-MAR-2010, integrated into UniProtKB/Swiss-Prot.
DT   02-MAR-2010, sequence version 1.
DT   25-MAY-2022, entry version 23.
DE   RecName: Full=Alpha-conotoxin-like Ms20.5;
DE   Flags: Precursor;
OS   Conus mustelinus (Weasel cone).
OC   Eukaryota; Metazoa; Spiralia; Lophotrochozoa; Mollusca; Gastropoda;
OC   Caenogastropoda; Neogastropoda; Conoidea; Conidae; Conus; Rhizoconus.
OX   NCBI_TaxID=101309;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 46-78,
RP   GAMMA-CARBOXYGLUTAMATION AT GLU-50, HYDROXYLATION AT PRO-56, AND SUBUNIT.
RC   TISSUE=Venom, and Venom duct;
RX   PubMed=19275168; DOI=10.1021/bi9000326;
RA   Loughnan M.L., Nicke A., Lawrence N., Lewis R.J.;
RT   "Novel alpha D-conopeptides and their precursors identified by cDNA cloning
RT   define the D-conotoxin superfamily.";
RL   Biochemistry 48:3717-3729(2009).
CC   -!- FUNCTION: Alpha-conotoxins act on postsynaptic membranes, they bind to
CC       the nicotinic acetylcholine receptors (nAChR) and thus inhibit them.
CC       This toxin specifically blocks mammalian neuronal nAChR of the alpha-
CC       7/CHRNA7, alpha-3-beta-2/CHRNA3-CHRNB2 and alpha-4-beta-2/CHRNA4-CHRNB2
CC       subtypes (By similarity). {ECO:0000250}.
CC   -!- SUBUNIT: Hetero-, homo- or pseudo-homodimers (identical sequence,
CC       different post-translational modifications) (By similarity).
CC       Heterodimer of [carboxy'Glu-49', hydroxy'Pro-55']Ms20.3 and
CC       [carboxyGlu-50, hydroxyPro-56]Ms20.5 may exist. {ECO:0000250,
CC       ECO:0000269|PubMed:19275168}.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom duct.
CC   -!- DOMAIN: The cysteine framework is XX (C-CC-C-CC-C-C-C-C).
CC   -!- PTM: Contains 5 disulfide bonds. {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the conotoxin D superfamily. {ECO:0000305}.
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DR   AlphaFoldDB; P0CE30; -.
DR   SMR; P0CE30; -.
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.
PE   1: Evidence at protein level;
KW   Acetylcholine receptor inhibiting toxin; Direct protein sequencing;
KW   Disulfide bond; Gamma-carboxyglutamic acid; Hydroxylation;
KW   Ion channel impairing toxin; Neurotoxin; Postsynaptic neurotoxin; Secreted;
KW   Signal; Toxin.
FT   SIGNAL          1..24
FT                   /evidence="ECO:0000255"
FT   PROPEP          25..45
FT                   /evidence="ECO:0000269|PubMed:19275168"
FT                   /id="PRO_0000391818"
FT   CHAIN           46..95
FT                   /note="Alpha-conotoxin-like Ms20.5"
FT                   /id="PRO_0000391819"
FT   MOD_RES         50
FT                   /note="4-carboxyglutamate"
FT                   /evidence="ECO:0000269|PubMed:19275168"
FT   MOD_RES         56
FT                   /note="4-hydroxyproline"
FT                   /evidence="ECO:0000269|PubMed:19275168"
SQ   SEQUENCE   95 AA;  10194 MW;  B27B4CE801E1C38C CRC64;
     MPKLAVVLLV LLILPLSYFD AAGGQAAEGD RRGNGLARYL QRGGRDNEAE CQINTPGSSW
     GKCCLTRMCG PMCCARSGCT CVYHWRRGHG CSCPG