ID   3SUB_DENAN              Reviewed;          63 AA.
AC   P60237;
DT   16-JAN-2004, integrated into UniProtKB/Swiss-Prot.
DT   16-JAN-2004, sequence version 1.
DT   25-MAY-2022, entry version 67.
DE   RecName: Full=Muscarinic toxin 2 {ECO:0000303|PubMed:10531397};
DE            Short=m2-toxin {ECO:0000303|PubMed:10531397};
OS   Dendroaspis angusticeps (Eastern green mamba) (Naja angusticeps).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Elapidae; Elapinae; Dendroaspis.
OX   NCBI_TaxID=8618;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 1-53, FUNCTION, AND
RP   SUBCELLULAR LOCATION.
RC   TISSUE=Venom, and Venom gland;
RX   PubMed=10531397; DOI=10.1124/mol.56.5.933;
RA   Carsi J.M., Valentine H.H., Potter L.T.;
RT   "m2-toxin: a selective ligand for M2 muscarinic receptors.";
RL   Mol. Pharmacol. 56:933-937(1999).
CC   -!- FUNCTION: Blocks M2 muscarinic acetylcholine receptors (CHRM2). Fully
CC       blocks the binding of N-methylscopolamine (NMS) and oxotremorine-M to
CC       M2 receptors, slightly increased NMS binding to M1 receptors.
CC       {ECO:0000269|PubMed:10531397}.
CC   -!- SUBUNIT: Monomer. {ECO:0000303|PubMed:10531397}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:10531397}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
CC   -!- MISCELLANEOUS: Has no effect on M3, M4 and M5 muscarinic acetylcholine
CC       receptors. {ECO:0000269|PubMed:10531397}.
CC   -!- SIMILARITY: Belongs to the snake three-finger toxin family. Short-chain
CC       subfamily. Type B muscarinic toxin sub-subfamily. {ECO:0000305}.
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DR   AlphaFoldDB; P60237; -.
DR   SMR; P60237; -.
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   InterPro; IPR018354; Snake_toxin_con_site.
DR   SUPFAM; SSF57302; SSF57302; 1.
DR   PROSITE; PS00272; SNAKE_TOXIN; 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; Toxin.
FT   CHAIN           1..63
FT                   /note="Muscarinic toxin 2"
FT                   /evidence="ECO:0000305|PubMed:10531397"
FT                   /id="PRO_0000093647"
FT   DISULFID        3..22
FT                   /evidence="ECO:0000250|UniProtKB:P0C1Z0"
FT   DISULFID        17..42
FT                   /evidence="ECO:0000250|UniProtKB:P0C1Z0"
FT   DISULFID        44..55
FT                   /evidence="ECO:0000250|UniProtKB:P0C1Z0"
FT   DISULFID        56..61
FT                   /evidence="ECO:0000250|UniProtKB:P0C1Z0"
SQ   SEQUENCE   63 AA;  7100 MW;  19C000A0931AD940 CRC64;
     RICHSQMSSQ PPTTTFCRVN SCYRRTLRDP HDPRGTIIVR GCGCPRMKPG TKLECCTSDK
     CNV