ID   TXH22_CYRSC             Reviewed;          37 AA.
AC   P82960;
DT   04-MAY-2001, integrated into UniProtKB/Swiss-Prot.
DT   04-MAY-2001, sequence version 1.
DT   25-MAY-2022, entry version 69.
DE   RecName: Full=U1-theraphotoxin-Hs1b;
DE            Short=U1-TRTX-Hs1b;
DE   AltName: Full=Huwentoxin-2 form 2;
DE   AltName: Full=Huwentoxin-II;
DE            Short=HwTx-II;
OS   Cyriopagopus schmidti (Chinese bird spider) (Haplopelma schmidti).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; Araneae;
OC   Mygalomorphae; Theraphosidae; Cyriopagopus.
OX   NCBI_TaxID=29017;
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, AND MASS SPECTROMETRY.
RC   TISSUE=Venom;
RX   PubMed=10424342; DOI=10.1034/j.1399-3011.1999.00039.x;
RA   Shu Q., Liang S.-P.;
RT   "Purification and characterization of huwentoxin-II, a neurotoxic peptide
RT   from the venom of the Chinese bird spider Selenocosmia huwena.";
RL   J. Pept. Res. 53:486-491(1999).
RN   [2]
RP   DISULFIDE BONDS.
RX   PubMed=11298747; DOI=10.1046/j.1432-1327.2001.02109.x;
RA   Shu Q., Huang R., Liang S.-P.;
RT   "Assignment of the disulfide bonds of huwentoxin-II by Edman degradation
RT   sequencing and stepwise thiol modification.";
RL   Eur. J. Biochem. 268:2301-2307(2001).
CC   -!- FUNCTION: Lethal neurotoxin that blocks neuromuscular transmission.
CC       Acts cooperatively to potentiate the activity of huwentoxin-I.
CC       {ECO:0000269|PubMed:10424342}.
CC   -!- SUBUNIT: Form 1 and form 2 may dimerize.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC   -!- MASS SPECTROMETRY: Mass=4305.2; Method=MALDI;
CC       Evidence={ECO:0000269|PubMed:10424342};
CC   -!- SIMILARITY: Belongs to the neurotoxin 12 (Hwtx-2) family. 02 (Hwtx-2)
CC       subfamily. {ECO:0000305}.
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DR   AlphaFoldDB; P82960; -.
DR   SMR; P82960; -.
DR   ArachnoServer; AS000329; U1-theraphotoxin-Hs1b.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0035792; C:host cell postsynaptic membrane; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   InterPro; IPR012625; Toxin_20.
DR   Pfam; PF08089; Toxin_20; 1.
DR   PROSITE; PS60022; HWTX_2; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Neurotoxin;
KW   Postsynaptic neurotoxin; Secreted; Toxin.
FT   PEPTIDE         1..37
FT                   /note="U1-theraphotoxin-Hs1b"
FT                   /id="PRO_0000044983"
FT   DISULFID        4..18
FT                   /evidence="ECO:0000269|PubMed:11298747"
FT   DISULFID        8..29
FT                   /evidence="ECO:0000269|PubMed:11298747"
FT   DISULFID        23..34
FT                   /evidence="ECO:0000269|PubMed:11298747"
SQ   SEQUENCE   37 AA;  4305 MW;  E0F9F85AA0356382 CRC64;
     LFECSFSCEQ EKEGDKPCKK KKCKGGWKCK FNMCVKV