TXC8_CUPSA
ID TXC8_CUPSA Reviewed; 117 AA.
AC B3EWS5; A0A4Y5UGJ3;
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-8 {ECO:0000303|PubMed:22672445};
DE Contains:
DE RecName: Full=CSTX-8 A chain {ECO:0000303|PubMed:22672445};
DE Contains:
DE RecName: Full=CSTX-8 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 THR-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-8 A chain]: Mass=4369.872;
CC Method=Electrospray; Evidence={ECO:0000269|PubMed:22672445};
CC -!- MASS SPECTROMETRY: [CSTX-8 B chain]: Mass=3475.802;
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; MH754554; QDC23089.1; -; mRNA.
DR EMBL; MH754555; QDC23090.1; -; mRNA.
DR AlphaFoldDB; B3EWS5; -.
DR SMR; B3EWS5; -.
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_0000452339"
FT PEPTIDE 48..81
FT /note="CSTX-8 A chain"
FT /evidence="ECO:0000269|PubMed:22672445"
FT /id="PRO_0000421198"
FT PROPEP 82..87
FT /evidence="ECO:0000305|PubMed:22672445"
FT /id="PRO_0000452340"
FT PEPTIDE 88..116
FT /note="CSTX-8 B chain"
FT /evidence="ECO:0000269|PubMed:22672445"
FT /id="PRO_0000421199"
FT MOD_RES 116
FT /note="Threonine 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; 13415 MW; 85B370749925605E CRC64;
MKVLVICAVL FLAIFSNSSA ETEDDFLEDE SFQADDVIPF LASEQVRSDC TLRNHDCTDD
RHSCCRSKMF KDVCKCFYPS QRSETDRAKK ELCTCQQPKH LKYIEKGLQK AKDYATG
