ID   TX3_PHONI               Reviewed;          19 AA.
AC   P31010;
DT   01-JUL-1993, integrated into UniProtKB/Swiss-Prot.
DT   01-JUL-1993, sequence version 1.
DT   25-MAY-2022, entry version 53.
DE   RecName: Full=U7-ctenitoxin-Pn1b;
DE            Short=U7-CNTX-Pn1b;
DE   AltName: Full=Neurotoxin Tx3;
DE   Flags: Fragment;
OS   Phoneutria nigriventer (Brazilian armed spider) (Ctenus nigriventer).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; Araneae;
OC   Araneomorphae; Entelegynae; Lycosoidea; Ctenidae; Phoneutria.
OX   NCBI_TaxID=6918;
RN   [1]
RP   PROTEIN SEQUENCE.
RC   TISSUE=Venom;
RX   PubMed=1801316; DOI=10.1016/0041-0101(91)90195-w;
RA   Rezende L. Jr., Cordeiro M.N., Oliveira E.B., Diniz C.R.;
RT   "Isolation of neurotoxic peptides from the venom of the 'armed' spider
RT   Phoneutria nigriventer.";
RL   Toxicon 29:1225-1233(1991).
CC   -!- FUNCTION: Antagonist of L-type calcium channels (Cav1/CACNA1).
CC       {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
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DR   PIR; C39305; C39305.
DR   AlphaFoldDB; P31010; -.
DR   ArachnoServer; AS000275; U7-ctenitoxin-Pn1b (N-terminal fragment).
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0005246; F:calcium channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
PE   1: Evidence at protein level;
KW   Calcium channel impairing toxin; Direct protein sequencing;
KW   Ion channel impairing toxin; Neurotoxin; Secreted; Toxin;
KW   Voltage-gated calcium channel impairing toxin.
FT   CHAIN           1..>19
FT                   /note="U7-ctenitoxin-Pn1b"
FT                   /id="PRO_0000087642"
FT   NON_TER         19
SQ   SEQUENCE   19 AA;  2244 MW;  3214E89CF10F7587 CRC64;
     GCIGRNESQK KDNVYKFKE