ID   3L2P_PSETE              Reviewed;         103 AA.
AC   Q9W7J5;
DT   13-APR-2004, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1999, sequence version 1.
DT   25-MAY-2022, entry version 79.
DE   RecName: Full=Pseudonajatoxin b homolog;
DE   AltName: Full=Pt-bp;
DE   Flags: Precursor;
OS   Pseudonaja textilis (Eastern brown snake).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Elapidae; Acanthophiinae; Pseudonaja.
OX   NCBI_TaxID=8673;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA / MRNA], PROTEIN SEQUENCE OF 22-36, AND
RP   SUBCELLULAR LOCATION.
RC   TISSUE=Liver, Venom, and Venom gland;
RX   PubMed=11535126; DOI=10.1042/0264-6021:3580647;
RA   Gong N.L., Armugam A., Mirtschin P., Jeyaseelan K.;
RT   "Cloning and characterization of the pseudonajatoxin b precursor.";
RL   Biochem. J. 358:647-656(2001).
RN   [2]
RP   PROTEIN SEQUENCE OF 22-33, AND IDENTIFICATION BY MASS SPECTROMETRY.
RC   TISSUE=Venom;
RX   PubMed=16284125; DOI=10.1074/mcp.m500270-mcp200;
RA   Birrell G.W., Earl S., Masci P.P., de Jersey J., Wallis T.P., Gorman J.J.,
RA   Lavin M.F.;
RT   "Molecular diversity in venom from the Australian Brown snake, Pseudonaja
RT   textilis.";
RL   Mol. Cell. Proteomics 5:379-389(2006).
CC   -!- FUNCTION: Binds with high affinity to muscular (alpha-1/CHRNA1) and
CC       neuronal (alpha-7/CHRNA7) nicotinic acetylcholine receptor (nAChR) and
CC       inhibits acetylcholine from binding to the receptor, thereby impairing
CC       neuromuscular and neuronal transmission.
CC       {ECO:0000250|UniProtKB:P60615}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:11535126}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the snake three-finger toxin family. Long-chain
CC       subfamily. Type II alpha-neurotoxin sub-subfamily. {ECO:0000305}.
CC   -!- CAUTION: Could be the precursor of pseudonajatoxin b. But there are
CC       three amino-acid differences that could be strain variations or due to
CC       a multigene family. {ECO:0000305}.
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DR   EMBL; AF082982; AAD40974.1; -; mRNA.
DR   EMBL; AY027493; AAK15774.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q9W7J5; -.
DR   SMR; Q9W7J5; -.
DR   Proteomes; UP000472273; Unplaced.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
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.
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   Acetylcholine receptor inhibiting toxin; Direct protein sequencing;
KW   Disulfide bond; Ion channel impairing toxin; Neurotoxin;
KW   Postsynaptic neurotoxin; Reference proteome; Secreted; Signal; Toxin.
FT   SIGNAL          1..21
FT                   /evidence="ECO:0000269|PubMed:11535126,
FT                   ECO:0000269|PubMed:16284125"
FT   CHAIN           22..103
FT                   /note="Pseudonajatoxin b homolog"
FT                   /id="PRO_0000035432"
FT   DISULFID        24..42
FT                   /evidence="ECO:0000250"
FT   DISULFID        35..63
FT                   /evidence="ECO:0000250"
FT   DISULFID        48..52
FT                   /evidence="ECO:0000250"
FT   DISULFID        67..79
FT                   /evidence="ECO:0000250"
FT   DISULFID        80..85
FT                   /evidence="ECO:0000250"
FT   CONFLICT        26
FT                   /note="I -> K (in Ref. 2; AA sequence)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        29
FT                   /note="D -> Y (in Ref. 2; AA sequence)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        33
FT                   /note="K -> E (in Ref. 2; AA sequence)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   103 AA;  11269 MW;  399A8413B6FDDC56 CRC64;
     MKTLLLTLVV VTIVCLDLGY TRTCFITPDV KSKPCPPGQE VCYTKTWCDG FCGIRGKRVD
     LGCAATCPTP KKTGIDIICC STDDCNTFPL RPRGRLSSIK DHP