VKTHB_BUNFL
ID VKTHB_BUNFL Reviewed; 83 AA.
AC Q7T2Q6;
DT 09-JAN-2007, integrated into UniProtKB/Swiss-Prot.
DT 01-OCT-2003, sequence version 1.
DT 25-MAY-2022, entry version 64.
DE RecName: Full=Kunitz-type serine protease inhibitor homolog beta-bungarotoxin B chain;
DE Flags: Precursor;
OS Bungarus flaviceps flaviceps (Red-headed krait).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC Serpentes; Colubroidea; Elapidae; Bungarinae; Bungarus.
OX NCBI_TaxID=8615;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 25-50, SUBUNIT, AND
RP IDENTIFICATION BY MASS SPECTROMETRY.
RC TISSUE=Venom gland;
RX PubMed=16458338; DOI=10.1016/j.toxicon.2005.12.004;
RA Yanoshita R., Ogawa Y., Murayama N., Omori-Satoh T., Saguchi K.,
RA Higuchi S., Khow O., Chanhome L., Samejima Y., Sitprija V.;
RT "Molecular cloning of the major lethal toxins from two kraits (Bungarus
RT flaviceps and Bungarus candidus).";
RL Toxicon 47:416-424(2006).
RN [2]
RP FUNCTION, AND SUBUNIT.
RC TISSUE=Venom;
RX PubMed=11738240; DOI=10.1016/s0041-0101(01)00235-5;
RA Khow O., Chanhome L., Omori-Satoh T., Sitprija V.;
RT "Isolation of the major lethal toxin in the venom of Bungarus flaviceps.";
RL Toxicon 40:463-469(2002).
CC -!- FUNCTION: Beta-bungarotoxin is a presynaptic neurotoxin of the venom.
CC The B chain is homologous to venom basic protease inhibitors but has no
CC protease inhibitor activity and is non-toxic.
CC {ECO:0000269|PubMed:11738240}.
CC -!- SUBUNIT: Heterodimer with beta-bungarotoxin A1 chain; disulfide-linked.
CC The A chain has phospholipase A2 activity and the B chain shows
CC homology with the basic protease inhibitors.
CC {ECO:0000269|PubMed:11738240, ECO:0000269|PubMed:16458338}.
CC -!- SUBCELLULAR LOCATION: Secreted.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC -!- SIMILARITY: Belongs to the venom Kunitz-type family. {ECO:0000305}.
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DR EMBL; AB112358; BAC77654.1; -; mRNA.
DR AlphaFoldDB; Q7T2Q6; -.
DR SMR; Q7T2Q6; -.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0004867; F:serine-type endopeptidase inhibitor activity; IEA:InterPro.
DR GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR CDD; cd00109; KU; 1.
DR Gene3D; 4.10.410.10; -; 1.
DR InterPro; IPR002223; Kunitz_BPTI.
DR InterPro; IPR036880; Kunitz_BPTI_sf.
DR InterPro; IPR020901; Prtase_inh_Kunz-CS.
DR Pfam; PF00014; Kunitz_BPTI; 1.
DR PRINTS; PR00759; BASICPTASE.
DR SMART; SM00131; KU; 1.
DR SUPFAM; SSF57362; SSF57362; 1.
DR PROSITE; PS00280; BPTI_KUNITZ_1; 1.
DR PROSITE; PS50279; BPTI_KUNITZ_2; 1.
PE 1: Evidence at protein level;
KW Direct protein sequencing; Disulfide bond; Neurotoxin;
KW Presynaptic neurotoxin; Secreted; Signal; Toxin.
FT SIGNAL 1..24
FT /evidence="ECO:0000269|PubMed:16458338"
FT CHAIN 25..83
FT /note="Kunitz-type serine protease inhibitor homolog beta-
FT bungarotoxin B chain"
FT /id="PRO_5000050834"
FT DOMAIN 31..81
FT /note="BPTI/Kunitz inhibitor"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT DISULFID 31..81
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT DISULFID 40..64
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT DISULFID 56..77
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT DISULFID 79
FT /note="Interchain (with an A chain)"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
SQ SEQUENCE 83 AA; 9334 MW; 2DB104419C64BE8D CRC64;
MSSGSLLLLL GLLTLLAELT PVSSRKRHPD CDKPPNKKRC TGHIPAFYYN PQRKTCERFS
YGGCKGNGNH FKTPQLCMCH CHE
