ID   VKT2_CYRHA              Reviewed;          88 AA.
AC   D2Y2F3;
DT   02-NOV-2010, integrated into UniProtKB/Swiss-Prot.
DT   02-MAR-2010, sequence version 1.
DT   03-AUG-2022, entry version 34.
DE   RecName: Full=Kunitz-type U15-theraphotoxin-Hhn1b;
DE            Short=U15-TRTX-Hhn1b;
DE   AltName: Full=Kunitz-type serine protease inhibitor hainantoxin-XI-2;
DE            Short=HNTX-XI-2;
DE   Flags: Precursor;
OS   Cyriopagopus hainanus (Chinese bird spider) (Haplopelma hainanum).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; Araneae;
OC   Mygalomorphae; Theraphosidae; Haplopelma.
OX   NCBI_TaxID=209901;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC   TISSUE=Venom gland;
RX   PubMed=20192277; DOI=10.1021/pr1000016;
RA   Tang X., Zhang Y., Hu W., Xu D., Tao H., Yang X., Li Y., Jiang L.,
RA   Liang S.;
RT   "Molecular diversification of peptide toxins from the tarantula Haplopelma
RT   hainanum (Ornithoctonus hainana) venom based on transcriptomic, peptidomic,
RT   and genomic analyses.";
RL   J. Proteome Res. 9:2550-2564(2010).
CC   -!- FUNCTION: Serine protease inhibitor that inhibits chymotrypsin and
CC       blocks voltage-gated potassium channels (Kv). {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC   -!- SIMILARITY: Belongs to the venom Kunitz-type family. 03 (sub-Kunitz)
CC       subfamily. {ECO:0000305}.
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DR   EMBL; GU293030; ADB56846.1; -; mRNA.
DR   AlphaFoldDB; D2Y2F3; -.
DR   SMR; D2Y2F3; -.
DR   ArachnoServer; AS001598; U15-theraphotoxin-Hhn1b.
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:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   GO; GO:0044562; P:envenomation resulting in negative regulation of voltage-gated potassium channel activity in another organism; IEA:UniProt.
DR   CDD; cd00109; KU; 1.
DR   Gene3D; 4.10.410.10; -; 1.
DR   InterPro; IPR002223; Kunitz_BPTI.
DR   InterPro; IPR036880; Kunitz_BPTI_sf.
DR   Pfam; PF00014; Kunitz_BPTI; 1.
DR   PRINTS; PR00759; BASICPTASE.
DR   SMART; SM00131; KU; 1.
DR   SUPFAM; SSF57362; SSF57362; 1.
DR   PROSITE; PS50279; BPTI_KUNITZ_2; 1.
PE   2: Evidence at transcript level;
KW   Disulfide bond; Ion channel impairing toxin;
KW   Potassium channel impairing toxin; Protease inhibitor; Secreted;
KW   Serine protease inhibitor; Signal; Toxin;
KW   Voltage-gated potassium channel impairing toxin.
FT   SIGNAL          1..27
FT                   /evidence="ECO:0000255"
FT   PROPEP          28..33
FT                   /evidence="ECO:0000250"
FT                   /id="PRO_0000400980"
FT   PEPTIDE         34..88
FT                   /note="Kunitz-type U15-theraphotoxin-Hhn1b"
FT                   /id="PRO_0000400981"
FT   DOMAIN          37..85
FT                   /note="BPTI/Kunitz inhibitor"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   SITE            47..48
FT                   /note="Reactive bond for chymotrypsin"
FT                   /evidence="ECO:0000250"
FT   DISULFID        37..85
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   DISULFID        60..81
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
SQ   SEQUENCE   88 AA;  9859 MW;  533DAEC17975CA47 CRC64;
     MGTARFLRAV LLLSVLLMVT FPALLSAEHH DGRVDICRLP SDSGDCLRFF EMWYFDGTTC
     TKFVYGGYGG NDNRFPTEKA CVKRCAKA