ID   TXFK2_PSACA             Reviewed;          65 AA.
AC   P0C202;
DT   31-OCT-2006, integrated into UniProtKB/Swiss-Prot.
DT   31-OCT-2006, sequence version 1.
DT   25-MAY-2022, entry version 33.
DE   RecName: Full=U2-theraphotoxin-Pc1a;
DE            Short=U2-TRTX-Pc1a;
DE   AltName: Full=Psalmopeotoxin II;
DE   AltName: Full=Psalmopeotoxin-2;
DE   AltName: Full=Psalmopoeus cambridgei Falciparum killer 2;
DE            Short=PcFK2;
DE   Flags: Precursor;
OS   Psalmopoeus cambridgei (Trinidad chevron tarantula).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; Araneae;
OC   Mygalomorphae; Theraphosidae; Psalmopoeus.
OX   NCBI_TaxID=179874;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], PARTIAL PROTEIN SEQUENCE, FUNCTION, AND MASS
RP   SPECTROMETRY.
RC   TISSUE=Venom, and Venom gland;
RX   PubMed=15304333; DOI=10.1016/j.febslet.2004.07.019;
RA   Choi S.-J., Parent R., Guillaume C., Deregnaucourt C., Delarbre C.,
RA   Ojcius D.M., Montagne J.-J., Celerier M.-L., Phelipot A., Amiche M.,
RA   Molgo J., Camadro J.-M., Guette C.;
RT   "Isolation and characterization of Psalmopeotoxin I and II: two novel
RT   antimalarial peptides from the venom of the tarantula Psalmopoeus
RT   cambridgei.";
RL   FEBS Lett. 572:109-117(2004).
CC   -!- FUNCTION: Possesses strong antiplasmodial activity against the intra-
CC       erythrocyte stage of P.falciparum in vitro. IC(50) for inhibiting
CC       P.falciparum growth is 1.15 uM. Specifically interacts with infected
CC       erythrocytes. Does not lyse erythrocytes, is not cytotoxic to nucleated
CC       mammalian cells, and does not inhibit neuromuscular function. Has
CC       neither antibacterial nor antifungal activity.
CC       {ECO:0000269|PubMed:15304333}.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin. {ECO:0000250}.
CC   -!- MASS SPECTROMETRY: Mass=2948.30; Method=MALDI;
CC       Evidence={ECO:0000269|PubMed:15304333};
CC   -!- MISCELLANEOUS: Usually endopeptidases cleave the propeptide at the C-
CC       terminus of the basic doublet (Arg-37-38-Arg), but here, it seems that
CC       the endopeptidase cleaves the precursor within the doublet.
CC   -!- SIMILARITY: Belongs to the neurotoxin 36 family. 02 subfamily.
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DR   AlphaFoldDB; P0C202; -.
DR   SMR; P0C202; -.
DR   ArachnoServer; AS000319; U2-theraphotoxin-Pc1a.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
PE   1: Evidence at protein level;
KW   Cleavage on pair of basic residues; Direct protein sequencing;
KW   Disulfide bond; Knottin; Secreted; Signal; Toxin.
FT   SIGNAL          1..20
FT                   /evidence="ECO:0000255"
FT   PROPEP          21..36
FT                   /id="PRO_0000256696"
FT   PEPTIDE         38..65
FT                   /note="U2-theraphotoxin-Pc1a"
FT                   /id="PRO_0000256697"
FT   DISULFID        39..56
FT                   /evidence="ECO:0000250"
FT   DISULFID        46..59
FT                   /evidence="ECO:0000250"
FT   DISULFID        55..64
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   65 AA;  6994 MW;  0DAB76A7C06E7F73 CRC64;
     MGFKLVLFIA VLTLVGSSNA EISAKMDSRD SPMIQERRCL PAGKTCVRGP MRVPCCGSCS
     QNKCT