VKTH4_BUNMU
ID VKTH4_BUNMU Reviewed; 85 AA.
AC Q1RPT0;
DT 16-JUN-2009, integrated into UniProtKB/Swiss-Prot.
DT 16-MAY-2006, sequence version 1.
DT 25-MAY-2022, entry version 50.
DE RecName: Full=Kunitz-type serine protease inhibitor homolog beta-bungarotoxin B4 chain;
DE Flags: Precursor;
OS Bungarus multicinctus (Many-banded krait).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC Serpentes; Colubroidea; Elapidae; Bungarinae; Bungarus.
OX NCBI_TaxID=8616;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], AND SUBUNIT.
RC TISSUE=Venom, and Venom gland;
RX PubMed=16457863; DOI=10.1016/j.toxicon.2005.11.009;
RA Cheng Y.-C., Chen K.-C., Lin S.-K., Chang L.-S.;
RT "Divergence of genes encoding B chains of beta-bungarotoxins.";
RL Toxicon 47:322-329(2006).
CC -!- FUNCTION: Beta-bungarotoxins are presynaptic neurotoxins of the venom.
CC The B chain is homologous to venom basic protease inhibitors but has no
CC protease inhibitor activity and blocks voltage-gated potassium channels
CC (Kv) (By similarity). {ECO:0000250}.
CC -!- SUBUNIT: Heterodimer; disulfide-linked. The A chains have phospholipase
CC A2 activity and the B chains show homology with the basic protease
CC inhibitors. {ECO:0000269|PubMed:16457863}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250}.
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; AM050152; CAJ18319.1; -; Genomic_DNA.
DR AlphaFoldDB; Q1RPT0; -.
DR SMR; Q1RPT0; -.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0015459; F:potassium channel regulator activity; IEA:UniProtKB-KW.
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 Disulfide bond; Ion channel impairing toxin; Neurotoxin;
KW Potassium channel impairing toxin; Presynaptic neurotoxin; Secreted;
KW Signal; Toxin; Voltage-gated potassium channel impairing toxin.
FT SIGNAL 1..24
FT /evidence="ECO:0000250"
FT CHAIN 25..85
FT /note="Kunitz-type serine protease inhibitor homolog beta-
FT bungarotoxin B4 chain"
FT /id="PRO_5000076282"
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 85 AA; 9499 MW; FF25A59AF92BF2AA CRC64;
MSSGGLLLLL GLLTLCAELT PVSSRKRHPD CDKPPDTKIC QTVVRAFYYK PSAKRCVQFR
YGGCNGNGNH FKSDHLCRCE CLEYS
