ID   TX27A_CUPSA             Reviewed;          51 AA.
AC   B3EWT3;
DT   06-FEB-2013, integrated into UniProtKB/Swiss-Prot.
DT   06-FEB-2013, sequence version 1.
DT   25-MAY-2022, entry version 21.
DE   RecName: Full=Toxin CSTX-18 {ECO:0000303|PubMed:22672445};
OS   Cupiennius salei (American wandering spider).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; Araneae;
OC   Araneomorphae; Entelegynae; Lycosoidea; Ctenidae; Cupiennius.
OX   NCBI_TaxID=6928;
RN   [1]
RP   PROTEIN SEQUENCE, MASS SPECTROMETRY, AND DISULFIDE BONDS.
RC   TISSUE=Venom;
RX   PubMed=22672445; DOI=10.1111/j.1742-4658.2012.08650.x;
RA   Trachsel C., Siegemund D., Kampfer U., Kopp L.S., Buhr C., Grossmann J.,
RA   Luthi C., Cunningham M., Nentwig W., Kuhn-Nentwig L., Schurch S.,
RA   Schaller J.;
RT   "Multicomponent venom of the spider Cupiennius salei: a bioanalytical
RT   investigation applying different strategies.";
RL   FEBS J. 279:2683-2694(2012).
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:22672445}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:22672445}.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin.
CC       {ECO:0000250|UniProtKB:P58604}.
CC   -!- PTM: Contains 4 disulfide bonds. {ECO:0000269|PubMed:22672445}.
CC   -!- MASS SPECTROMETRY: Mass=5598.828; Method=Electrospray;
CC       Evidence={ECO:0000269|PubMed:22672445};
CC   -!- SIMILARITY: Belongs to the neurotoxin 02 (plectoxin) family. 07
CC       subfamily. {ECO:0000255}.
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DR   AlphaFoldDB; B3EWT3; -.
DR   SMR; B3EWT3; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0008200; F:ion channel inhibitor activity; IEA:InterPro.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   InterPro; IPR004169; Spidertoxin.
DR   Pfam; PF02819; Toxin_9; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Knottin; Secreted; Toxin.
FT   PEPTIDE         1..51
FT                   /note="Toxin CSTX-18"
FT                   /evidence="ECO:0000269|PubMed:22672445"
FT                   /id="PRO_0000421190"
FT   DISULFID        9..22
FT                   /evidence="ECO:0000250|UniProtKB:P58604"
FT   DISULFID        14..27
FT                   /evidence="ECO:0000250|UniProtKB:P58604"
FT   DISULFID        21..36
FT                   /evidence="ECO:0000250|UniProtKB:P58604"
FT   DISULFID        29..34
FT                   /evidence="ECO:0000250|UniProtKB:P58604"
SQ   SEQUENCE   51 AA;  5611 MW;  81A53D20E942BC58 CRC64;
     GLWIKGNYCL RGRCLPGGRK CCNGRPCECF AKICSCKPKL IGKLSALKKH T