ID   TX34A_PHOKE             Reviewed;          54 AA.
AC   P84012;
DT   19-JUL-2004, integrated into UniProtKB/Swiss-Prot.
DT   05-JUL-2004, sequence version 1.
DT   25-MAY-2022, entry version 39.
DE   RecName: Full=U7-ctenitoxin-Pk1a;
DE            Short=U7-CNTX-Pk1a;
DE   AltName: Full=Neurotoxin PKTx36C1;
OS   Phoneutria keyserlingi (Brazilian wandering spider) (Ctenus keyserlingii).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; Araneae;
OC   Araneomorphae; Entelegynae; Lycosoidea; Ctenidae; Phoneutria.
OX   NCBI_TaxID=272754;
RN   [1] {ECO:0000305}
RP   PROTEIN SEQUENCE, SUBCELLULAR LOCATION, TISSUE SPECIFICITY, AND MASS
RP   SPECTROMETRY.
RC   TISSUE=Venom {ECO:0000269|PubMed:16278100};
RX   PubMed=16278100; DOI=10.1016/j.cbpc.2005.09.010;
RA   Richardson M., Pimenta A.M., Bemquerer M.P., Santoro M.M., Beirao P.S.,
RA   Lima M.E., Figueiredo S.G., Bloch C. Jr., Vasconcelos E.A., Campos F.A.,
RA   Gomes P.C., Cordeiro M.N.;
RT   "Comparison of the partial proteomes of the venoms of Brazilian spiders of
RT   the genus Phoneutria.";
RL   Comp. Biochem. Physiol. 142:173-187(2006).
RN   [2] {ECO:0000305}
RP   FUNCTION.
RA   Richardson M., Pimenta A.M.C., Bemquerer M.P., Santoro M.M.,
RA   Figueiredo S.G., Cordeiro M.N.;
RT   "Lethal neurotoxin PKTx36C1 from venom of Brazilian wandering spider
RT   Phoneutria keyserlingi has sequence similarities with toxins from other
RT   spiders which block voltage gated Na channels.";
RL   Submitted (JUN-2004) to UniProtKB.
CC   -!- FUNCTION: Blocks voltage-gated sodium channels (Nav). Causes immediate
CC       spastic paralysis and death in mice within 1 min of injection at dose
CC       levels of 1.5 ug per mouse. {ECO:0000269|Ref.2}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:16278100}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000269|PubMed:16278100}.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin. {ECO:0000305}.
CC   -!- MASS SPECTROMETRY: Mass=5970.2; Method=Electrospray;
CC       Evidence={ECO:0000269|PubMed:16278100};
CC   -!- SIMILARITY: Belongs to the neurotoxin 03 (Tx2) family. 04 subfamily.
CC       {ECO:0000305}.
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DR   AlphaFoldDB; P84012; -.
DR   SMR; P84012; -.
DR   ArachnoServer; AS000268; U7-ctenitoxin-Pk1a.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0017080; F:sodium channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   InterPro; IPR035285; CNTX.
DR   Pfam; PF17492; D_CNTX; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW   Knottin; Neurotoxin; Secreted; Toxin;
KW   Voltage-gated sodium channel impairing toxin.
FT   CHAIN           1..54
FT                   /note="U7-ctenitoxin-Pk1a"
FT                   /id="PRO_0000087627"
FT   DISULFID        3..17
FT                   /evidence="ECO:0000305"
FT   DISULFID        10..23
FT                   /evidence="ECO:0000305"
FT   DISULFID        14..52
FT                   /evidence="ECO:0000305"
FT   DISULFID        16..37
FT                   /evidence="ECO:0000305"
FT   DISULFID        25..35
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   54 AA;  5979 MW;  815F244706FAF660 CRC64;
     ATCAGQDKPC KETCDCCGER GECVCGLSYE GKYRCICRQG TFLIAWYKLA SCKK