ID   SRTXB_ATRBI             Reviewed;          21 AA.
AC   P80163;
DT   01-APR-1993, integrated into UniProtKB/Swiss-Prot.
DT   01-APR-1993, sequence version 1.
DT   25-MAY-2022, entry version 70.
DE   RecName: Full=Bibrotoxin;
DE            Short=BTX;
OS   Atractaspis bibronii (Bibron's mole viper) (Southern stiletto snake).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Lamprophiidae; Atractaspidinae; Atractaspis.
OX   NCBI_TaxID=61304;
RN   [1]
RP   PROTEIN SEQUENCE, AND FUNCTION.
RC   TISSUE=Venom;
RX   PubMed=8416802; DOI=10.1016/0014-5793(93)81142-m;
RA   Becker A., Dowdle E.B., Hechler U., Kauser K., Donner P., Schleuning W.-D.;
RT   "Bibrotoxin, a novel member of the endothelin/sarafotoxin peptide family,
RT   from the venom of the burrowing asp Atractaspis bibroni.";
RL   FEBS Lett. 315:100-103(1993).
CC   -!- FUNCTION: Vasoconstrictor activity. These toxins cause cardiac arrest
CC       probably as a result of coronary vasospasm. May act by displaying
CC       agonistic activities towards endothelin-1 and -2 receptors (EDNRA and
CC       EDNRB). {ECO:0000269|PubMed:8416802}.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC   -!- SIMILARITY: Belongs to the endothelin/sarafotoxin family.
CC       {ECO:0000305}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   PIR; S27039; S27039.
DR   AlphaFoldDB; P80163; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   GO; GO:0019229; P:regulation of vasoconstriction; IEA:InterPro.
DR   GO; GO:0042310; P:vasoconstriction; IEA:UniProtKB-KW.
DR   InterPro; IPR019764; Endothelin_toxin_CS.
DR   InterPro; IPR001928; Endothln-like_toxin.
DR   Pfam; PF00322; Endothelin; 1.
DR   SMART; SM00272; END; 1.
DR   PROSITE; PS00270; ENDOTHELIN; 1.
PE   1: Evidence at protein level;
KW   Cardiotoxin; Direct protein sequencing; Disulfide bond;
KW   G-protein coupled receptor impairing toxin; Secreted; Toxin; Vasoactive;
KW   Vasoconstrictor.
FT   PEPTIDE         1..21
FT                   /note="Bibrotoxin"
FT                   /id="PRO_0000043645"
FT   SITE            21
FT                   /note="Endothelin-receptor binding site"
FT                   /evidence="ECO:0000250"
FT   DISULFID        1..15
FT                   /evidence="ECO:0000250"
FT   DISULFID        3..11
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   21 AA;  2511 MW;  83A5DFB81D036AE2 CRC64;
     CSCADMTDKE CLYFCHQDVI W