ID   TX36A_PHOKE             Reviewed;          44 AA.
AC   P83896;
DT   19-JUL-2004, integrated into UniProtKB/Swiss-Prot.
DT   19-JAN-2010, sequence version 2.
DT   26-FEB-2020, entry version 35.
DE   RecName: Full=U4-ctenitoxin-Pk1a;
DE            Short=U4-CNTX-Pk1a;
DE   AltName: Full=Neurotoxin PKTx28C4;
DE   Flags: Fragment;
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 {ECO:0000305};
RN   [1]
RP   PROTEIN SEQUENCE, SUBCELLULAR LOCATION, TISSUE SPECIFICITY, AND MASS
RP   SPECTROMETRY.
RC   TISSUE=Venom;
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   "Potent neurotoxin PKTx28C4 from venom of Brazilian wandering spider
RT   Phoneutria keyserling.";
RL   Submitted (APR-2004) to UniProtKB.
CC   -!- FUNCTION: Neurotoxin. Causes spastic paralysis and death in mice within
CC       10 minutes at dose levels of 3 ug per mouse. {ECO:0000269|Ref.2,
CC       ECO:0000305}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:16278100,
CC       ECO:0000305}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000269|PubMed:16278100, ECO:0000305}.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin. {ECO:0000305}.
CC   -!- MASS SPECTROMETRY: Mass=5001.1; Method=Electrospray;
CC       Evidence={ECO:0000269|PubMed:16278100};
CC   -!- SIMILARITY: Belongs to the neurotoxin 03 (Tx2) family. 06 subfamily.
CC       {ECO:0000305}.
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DR   ArachnoServer; AS000246; U4-ctenitoxin-Pk1a.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
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; Knottin; Neurotoxin; Secreted;
KW   Toxin.
FT   PEPTIDE         1..>44
FT                   /note="U4-ctenitoxin-Pk1a"
FT                   /id="PRO_0000044969"
FT   DISULFID        4..18
FT                   /evidence="ECO:0000305"
FT   DISULFID        11..24
FT                   /evidence="ECO:0000305"
FT   DISULFID        15..42
FT                   /evidence="ECO:0000305"
FT   DISULFID        17..33
FT                   /evidence="ECO:0000305"
FT   DISULFID        26..31
FT                   /evidence="ECO:0000305"
FT   NON_TER         44
SQ   SEQUENCE   44 AA;  4689 MW;  F8CB37771D864B6B CRC64;
     KAKCADIDQP CKTSCDCCET KGACTCYKSG CVCRMGSFXA TCKK