ID   3NOHE_BUNMU             Reviewed;         103 AA.
AC   Q8JFX7;
DT   15-JAN-2008, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-2002, sequence version 1.
DT   25-MAY-2022, entry version 59.
DE   RecName: Full=Muscarinic toxin BM14 {ECO:0000303|PubMed:12437132};
DE   Flags: Precursor;
OS   Bungarus multicinctus (Many-banded krait).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Elapidae; Bungarinae; Bungarus.
OX   NCBI_TaxID=8616;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 22-103, FUNCTION,
RP   SITE, MASS SPECTROMETRY, AND SUBCELLULAR LOCATION.
RC   TISSUE=Liver, and Venom;
RX   PubMed=12437132; DOI=10.1515/bc.2002.158;
RA   Chung C., Wu B.N., Yang C.C., Chang L.S.;
RT   "Muscarinic toxin-like proteins from Taiwan banded krait (Bungarus
RT   multicinctus) venom: purification, characterization and gene
RT   organization.";
RL   Biol. Chem. 383:1397-1406(2002).
CC   -!- FUNCTION: This toxin inhibits the binding of [3H]quinuclidinyl
CC       benzilate to the M2 muscarinic acetylcholine (mAchR) receptor subtype
CC       (CHRM2). {ECO:0000269|PubMed:12437132}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:12437132}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
CC   -!- MASS SPECTROMETRY: Mass=9075; Method=Electrospray;
CC       Evidence={ECO:0000269|PubMed:12437132};
CC   -!- MISCELLANEOUS: Does not bind to receptor M1 (CHRM1). Is unable to
CC       compete with alpha-bungarotoxin for binding to nAchR at concentrations
CC       up to 100 uM. Does not manifest cytotoxicity toward myelogenous
CC       leukemia cells. Is not toxic to mice at doses up to 3 mg/kg.
CC       {ECO:0000269|PubMed:12437132}.
CC   -!- SIMILARITY: Belongs to the snake three-finger toxin family. Ancestral
CC       subfamily. Orphan group XVII sub-subfamily. {ECO:0000305}.
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DR   EMBL; AJ421675; CAD18848.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q8JFX7; -.
DR   SMR; Q8JFX7; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   CDD; cd00206; snake_toxin; 1.
DR   Gene3D; 2.10.60.10; -; 1.
DR   InterPro; IPR003571; Snake_3FTx.
DR   InterPro; IPR045860; Snake_toxin-like_sf.
DR   SUPFAM; SSF57302; SSF57302; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond;
KW   G-protein coupled acetylcholine receptor impairing toxin;
KW   G-protein coupled receptor impairing toxin; Neurotoxin;
KW   Postsynaptic neurotoxin; Secreted; Signal; Toxin.
FT   SIGNAL          1..21
FT                   /evidence="ECO:0000269|PubMed:12437132"
FT   CHAIN           22..103
FT                   /note="Muscarinic toxin BM14"
FT                   /evidence="ECO:0000269|PubMed:12437132"
FT                   /id="PRO_5000068180"
FT   SITE            58..59
FT                   /note="Plays a crucial role in mAChR-binding activity"
FT   DISULFID        24..45
FT                   /evidence="ECO:0000250|UniProtKB:P81782"
FT   DISULFID        27..37
FT                   /evidence="ECO:0000250|UniProtKB:P81782"
FT   DISULFID        38..72
FT                   /evidence="ECO:0000250|UniProtKB:P81782"
FT   DISULFID        76..90
FT                   /evidence="ECO:0000250|UniProtKB:P81782"
FT   DISULFID        91..96
FT                   /evidence="ECO:0000250|UniProtKB:P81782"
SQ   SEQUENCE   103 AA;  11390 MW;  DCF923F90446096D CRC64;
     MKTLLLTLVV VTIICLDLGY TEMCNMCVRP YPFMSSCCPE GQDRCYKSYW VNENGKQKKY
     HGKYPVILER GCVTACTGPG SGSIYNLYTC CPTNRCGSSS TSG