ID   TXC12_CUPSA             Reviewed;         117 AA.
AC   B3EWS6; A0A4Y5UH66;
DT   06-FEB-2013, integrated into UniProtKB/Swiss-Prot.
DT   07-APR-2021, sequence version 2.
DT   25-MAY-2022, entry version 17.
DE   RecName: Full=Toxin CSTX-12 {ECO:0000303|PubMed:22672445};
DE   Contains:
DE     RecName: Full=CSTX-12 A chain {ECO:0000303|PubMed:22672445};
DE   Contains:
DE     RecName: Full=CSTX-12 B chain {ECO:0000303|PubMed:22672445};
DE   Flags: Precursor;
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   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Venom gland;
RX   PubMed=30893800; DOI=10.3390/toxins11030167;
RA   Kuhn-Nentwig L., Langenegger N., Heller M., Koua D., Nentwig W.;
RT   "The dual prey-inactivation strategy of spiders-in-depth venomic analysis
RT   of Cupiennius salei.";
RL   Toxins 11:0-0(2019).
RN   [2]
RP   PROTEIN SEQUENCE OF 48-81 AND 88-116, MASS SPECTROMETRY, AMIDATION AT
RP   ALA-116, AND SUBCELLULAR LOCATION.
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   -!- FUNCTION: Synergistic toxin that induces or increases a cytolytic
CC       effect when combined with CSTX-1 (AC P81694) or CSTX-9 (AC P58604).
CC       When alone, has a weak insecticidal activity, with an unknown molecular
CC       target. {ECO:0000250|UniProtKB:P83919}.
CC   -!- SUBUNIT: Heterodimer of A and B chains; disulfide-linked (By
CC       similarity). Interacts with CSTX-1 (AC P81694), and with CSTX-9 (AC
CC       P58604) (By similarity). {ECO:0000250|UniProtKB:P83919}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:22672445}. Target
CC       cell membrane {ECO:0000250|UniProtKB:P83919}.
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   -!- MASS SPECTROMETRY: [CSTX-12 A chain]: Mass=4369.887;
CC       Method=Electrospray; Evidence={ECO:0000269|PubMed:22672445};
CC   -!- MASS SPECTROMETRY: [CSTX-12 B chain]: Mass=3409.862;
CC       Method=Electrospray; Evidence={ECO:0000269|PubMed:22672445};
CC   -!- SIMILARITY: Belongs to the neurotoxin 19 (CSTX) family. 12 subfamily.
CC       {ECO:0000255}.
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DR   EMBL; MH754557; QDC23092.1; -; mRNA.
DR   EMBL; MH754558; QDC23093.1; -; mRNA.
DR   AlphaFoldDB; B3EWS6; -.
DR   SMR; B3EWS6; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0016020; C:membrane; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   GO; GO:0019835; P:cytolysis; IEA:UniProtKB-KW.
DR   InterPro; IPR019553; Spider_toxin_CSTX_knottin.
DR   InterPro; IPR011142; Spider_toxin_CSTX_Knottin_CS.
DR   Pfam; PF10530; Toxin_35; 1.
DR   PROSITE; PS60029; SPIDER_CSTX; 1.
PE   1: Evidence at protein level;
KW   Amidation; Cytolysis; Direct protein sequencing; Disulfide bond; Knottin;
KW   Membrane; Neurotoxin; Secreted; Signal; Target cell membrane;
KW   Target membrane; Toxin.
FT   SIGNAL          1..20
FT                   /evidence="ECO:0000255"
FT   PROPEP          21..47
FT                   /evidence="ECO:0000305|PubMed:22672445"
FT                   /id="PRO_0000452337"
FT   PEPTIDE         48..81
FT                   /note="CSTX-12 A chain"
FT                   /evidence="ECO:0000269|PubMed:22672445"
FT                   /id="PRO_0000421181"
FT   PROPEP          82..87
FT                   /evidence="ECO:0000305|PubMed:22672445"
FT                   /id="PRO_0000452338"
FT   PEPTIDE         88..116
FT                   /note="CSTX-12 B chain"
FT                   /evidence="ECO:0000269|PubMed:22672445"
FT                   /id="PRO_0000421182"
FT   MOD_RES         116
FT                   /note="Alanine amide"
FT                   /evidence="ECO:0000269|PubMed:22672445"
FT   DISULFID        50..65
FT                   /evidence="ECO:0000250|UniProtKB:P83919"
FT   DISULFID        57..74
FT                   /evidence="ECO:0000250|UniProtKB:P83919"
FT   DISULFID        64..95
FT                   /note="Interchain (between A and B chains)"
FT                   /evidence="ECO:0000250|UniProtKB:P83919"
FT   DISULFID        76..93
FT                   /note="Interchain (between A and B chains)"
FT                   /evidence="ECO:0000250|UniProtKB:P83919"
SQ   SEQUENCE   117 AA;  13391 MW;  57DA913CC4443776 CRC64;
     MKVLVICAVL FLTIFSNSSA ETEDDFLEDE SFEADDVIPF LAREQVRSDC TLRNHDCTDD
     RHSCCRSKMF KDVCKCFYPS QRSDTARAKK ELCTCQQDKH LKFIEKGLQK AKVLVAG