ID   TX27_PHORI              Reviewed;          36 AA.
AC   P83892;
DT   19-JUL-2004, integrated into UniProtKB/Swiss-Prot.
DT   10-MAY-2004, sequence version 1.
DT   25-MAY-2022, entry version 52.
DE   RecName: Full=U4-ctenitoxin-Pr1a;
DE            Short=U4-CNTX-Pr1a;
DE   AltName: Full=Neurotoxin PRTx27C3;
OS   Phoneutria reidyi (Brazilian Amazonian armed spider) (Ctenus reidyi).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; Araneae;
OC   Araneomorphae; Entelegynae; Lycosoidea; Ctenidae; Phoneutria.
OX   NCBI_TaxID=272752 {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]
RP   PROTEIN SEQUENCE, FUNCTION, SUBCELLULAR LOCATION, TISSUE SPECIFICITY, AND
RP   MASS SPECTROMETRY.
RC   TISSUE=Venom;
RA   Lucio A.D., Champos F.V., Richardson M., Cordeiro M.N., Mazzoni M.S.C.,
RA   de Lima M.E., Pimenta A.M.C., Bemquerer M.P., Figueiredo S.G., Gomes P.C.,
RA   Beirao P.S.L.;
RT   "A new family of small (4kDa) neurotoxins from the venoms of spiders of the
RT   genus Poneutria.";
RL   Protein Pept. Lett. 15:700-708(2008).
CC   -!- FUNCTION: Neurotoxin. Causes spastic paralysis and death in mice.
CC       Moderate inhibitor of L-type calcium channels (Cav1/CACNA1).
CC       {ECO:0000269|Ref.2}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:16278100,
CC       ECO:0000269|Ref.2, ECO:0000305}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000269|PubMed:16278100, ECO:0000269|Ref.2, ECO:0000305}.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin. {ECO:0000250}.
CC   -!- MASS SPECTROMETRY: Mass=4043.64; Mass_error=0.22; Method=Electrospray;
CC       Evidence={ECO:0000269|Ref.2, ECO:0000305};
CC   -!- MASS SPECTROMETRY: Mass=4043.6; Method=Unknown;
CC       Evidence={ECO:0000269|PubMed:16278100, ECO:0000305};
CC   -!- SIMILARITY: Belongs to the neurotoxin 10 (Hwtx-1) family. 53 (PNTx27C4)
CC       subfamily. {ECO:0000305}.
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DR   AlphaFoldDB; P83892; -.
DR   SMR; P83892; -.
DR   ArachnoServer; AS000245; U4-ctenitoxin-Pr1a.
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:0008200; F:ion channel inhibitor activity; IEA:InterPro.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   InterPro; IPR011696; Huwentoxin-1.
DR   Pfam; PF07740; Toxin_12; 1.
PE   1: Evidence at protein level;
KW   Calcium channel impairing toxin; Direct protein sequencing; Disulfide bond;
KW   Ion channel impairing toxin; Knottin; Neurotoxin; Secreted; Toxin;
KW   Voltage-gated calcium channel impairing toxin.
FT   PEPTIDE         1..36
FT                   /note="U4-ctenitoxin-Pr1a"
FT                   /id="PRO_0000044978"
FT   DISULFID        3..17
FT                   /evidence="ECO:0000250"
FT   DISULFID        10..22
FT                   /evidence="ECO:0000250"
FT   DISULFID        16..34
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   36 AA;  4051 MW;  75ABA70C65FD9942 CRC64;
     IACAPRGLLC FRDKECCKGL TCKGRFVNTW PTFCLV