ID   TX22_PHONI              Reviewed;          35 AA.
AC   P83998;
DT   19-JUL-2004, integrated into UniProtKB/Swiss-Prot.
DT   05-JUL-2004, sequence version 1.
DT   25-MAY-2022, entry version 44.
DE   RecName: Full=U14-ctenitoxin-Pn1a;
DE            Short=U14-CNTX-Pn1a;
DE   AltName: Full=Neurotoxin PNTx22A0C1;
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] {ECO:0000305}
RP   PROTEIN SEQUENCE, SUBCELLULAR LOCATION, TISSUE SPECIFICITY, AND MASS
RP   SPECTROMETRY.
RC   TISSUE=Venom gland {ECO:0000269|Ref.1};
RA   Richardson M., Pimenta A.M.C., Bemquerer M.P., Santoro M.M.,
RA   Figueiredo S.G., Cordeiro M.N.;
RT   "New protein PNTx22A0C1 from venom of Brazilian armed spider Phoneutria
RT   nigriventer has strong sequence similarities with various arthropod
RT   neurotoxins and the Cucurbit family of proteinase inhibitors from plants.";
RL   Submitted (MAY-2004) to UniProtKB.
CC   -!- FUNCTION: Neurotoxin. {ECO:0000250|UniProtKB:P29426}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|Ref.1}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000269|Ref.1}.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin. {ECO:0000250}.
CC   -!- MASS SPECTROMETRY: Mass=4080.8; Method=Electrospray;
CC       Evidence={ECO:0000269|Ref.1};
CC   -!- SIMILARITY: Belongs to the protease inhibitor I7 (squash-type serine
CC       protease inhibitor) family. {ECO:0000305}.
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DR   AlphaFoldDB; P83998; -.
DR   ArachnoServer; AS000236; U14-ctenitoxin-Pn1a.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0004867; F:serine-type endopeptidase inhibitor activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   InterPro; IPR000737; Prot_inh_squash.
DR   InterPro; IPR011052; Proteinase_amylase_inhib_sf.
DR   Pfam; PF00299; Squash; 1.
DR   SUPFAM; SSF57027; SSF57027; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Knottin; Neurotoxin;
KW   Protease inhibitor; Secreted; Serine protease inhibitor; Toxin.
FT   PEPTIDE         1..35
FT                   /note="U14-ctenitoxin-Pn1a"
FT                   /id="PRO_0000044859"
FT   SITE            5..6
FT                   /note="Reactive bond"
FT                   /evidence="ECO:0000250|UniProtKB:P10291"
FT   DISULFID        3..17
FT                   /evidence="ECO:0000250"
FT   DISULFID        10..22
FT                   /evidence="ECO:0000250"
FT   DISULFID        16..32
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   35 AA;  4086 MW;  9616CF959FCC6117 CRC64;
     MPCPKILKQC KSDEDCCRGW KCFGFSIKDK MCISR