ID   3NO21_BUNCA             Reviewed;          86 AA.
AC   Q8AY51;
DT   15-JAN-2008, integrated into UniProtKB/Swiss-Prot.
DT   01-MAR-2003, sequence version 1.
DT   25-MAY-2022, entry version 72.
DE   RecName: Full=Weak toxin 1 {ECO:0000312|EMBL:AAL30059.1};
DE   Flags: Precursor;
OS   Bungarus candidus (Malayan krait).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Elapidae; Bungarinae; Bungarus.
OX   NCBI_TaxID=92438;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Venom gland;
RA   Tsai I.H., Wang Y.M., Hsu H.Y.;
RT   "Structural and functional genomics of Bungarus candidus.";
RL   Submitted (OCT-2001) to the EMBL/GenBank/DDBJ databases.
RN   [2]
RP   STRUCTURE BY NMR OF 22-86, AND DISULFIDE BONDS.
RA   Vivekanandan S., Jois S.D., Kini R.M., Troncone L.R.P., De Magalhaes L.,
RA   Ujikawa G.Y., Ramos A.T.;
RT   "NMR solution structure of bungatoxin from Bungarus candidus (Malayan
RT   krait) venom.";
RL   Submitted (JUN-2007) to the PDB data bank.
CC   -!- FUNCTION: Binds with low affinity to muscular (alpha-1-beta-1-delta-
CC       epsilon/CHRNA1-CHRNB1-CHRND-CHRNE) and very low affinity to neuronal
CC       (alpha-7/CHRNA7) nicotinic acetylcholine receptor (nAChR).
CC       {ECO:0000250|UniProtKB:O42255}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000305|Ref.1}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305|Ref.1}.
CC   -!- SIMILARITY: Belongs to the snake three-finger toxin family. Ancestral
CC       subfamily. Orphan group II sub-subfamily. {ECO:0000305}.
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DR   EMBL; AY057877; AAL30059.1; -; mRNA.
DR   PDB; 2JQP; NMR; -; A=22-86.
DR   PDBsum; 2JQP; -.
DR   AlphaFoldDB; Q8AY51; -.
DR   BMRB; Q8AY51; -.
DR   SMR; Q8AY51; -.
DR   EvolutionaryTrace; Q8AY51; -.
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   3D-structure; Acetylcholine receptor inhibiting toxin; Disulfide bond;
KW   Ion channel impairing toxin; Neurotoxin; Postsynaptic neurotoxin; Secreted;
KW   Signal; Toxin.
FT   SIGNAL          1..23
FT                   /evidence="ECO:0000255"
FT   CHAIN           24..86
FT                   /note="Weak toxin 1"
FT                   /id="PRO_0000316184"
FT   DISULFID        24..45
FT                   /evidence="ECO:0000269|Ref.2, ECO:0000312|PDB:2JQP"
FT   DISULFID        27..32
FT                   /evidence="ECO:0000269|Ref.2, ECO:0000312|PDB:2JQP"
FT   DISULFID        38..63
FT                   /evidence="ECO:0000269|Ref.2, ECO:0000312|PDB:2JQP"
FT   DISULFID        67..78
FT                   /evidence="ECO:0000269|Ref.2, ECO:0000312|PDB:2JQP"
FT   DISULFID        79..84
FT                   /evidence="ECO:0000269|Ref.2, ECO:0000312|PDB:2JQP"
FT   STRAND          23..26
FT                   /evidence="ECO:0007829|PDB:2JQP"
FT   STRAND          28..31
FT                   /evidence="ECO:0007829|PDB:2JQP"
FT   STRAND          34..37
FT                   /evidence="ECO:0007829|PDB:2JQP"
FT   STRAND          44..52
FT                   /evidence="ECO:0007829|PDB:2JQP"
FT   TURN            53..55
FT                   /evidence="ECO:0007829|PDB:2JQP"
FT   STRAND          56..65
FT                   /evidence="ECO:0007829|PDB:2JQP"
FT   STRAND          72..79
FT                   /evidence="ECO:0007829|PDB:2JQP"
FT   TURN            82..84
FT                   /evidence="ECO:0007829|PDB:2JQP"
SQ   SEQUENCE   86 AA;  9713 MW;  590A59EA8DBC8EB2 CRC64;
     MKTLLLTLVV VAIVCLDLGY TLTCLICPEK DCQKVHTCRN EEKICVKRFY DKNQLGWRAQ
     RGCAVSCPKA KPNETVQCCS TDKCNK