ID   PNTX_XIBTU              Reviewed;          78 AA.
AC   P0DQR5;
DT   23-FEB-2022, integrated into UniProtKB/Swiss-Prot.
DT   23-FEB-2022, sequence version 1.
DT   03-AUG-2022, entry version 3.
DE   RecName: Full=Putative neurotoxin {ECO:0000303|PubMed:24132120};
DE   Flags: Precursor;
OS   Xibalbanus tulumensis (Blind cave remipede) (Speleonectes tulumensis).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Crustacea; Remipedia;
OC   Nectiopoda; Speleonectidae; Xibalbanus.
OX   NCBI_TaxID=1519145;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], AND TISSUE SPECIFICITY.
RC   TISSUE=Venom gland;
RX   PubMed=24132120; DOI=10.1093/molbev/mst199;
RA   von Reumont B.M., Blanke A., Richter S., Alvarez F., Bleidorn C.,
RA   Jenner R.A.;
RT   "The first venomous crustacean revealed by transcriptomics and functional
RT   morphology: remipede venom glands express a unique toxin cocktail dominated
RT   by enzymes and a neurotoxin.";
RL   Mol. Biol. Evol. 31:48-58(2014).
CC   -!- FUNCTION: Probable neurotoxin. May act as a ion channel modulator that
CC       causes the immobilization of prey. This primitively aquatic arthropod
CC       may feed on crustaceans (or other arthropods), since its venom contains
CC       many chitinases. {ECO:0000305|PubMed:24132120}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000305|PubMed:24132120}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000269|PubMed:24132120}.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin. {ECO:0000305}.
CC   -!- MISCELLANEOUS: The transcriptomic profile of the venom glands of
CC       S.tulumensis shows that the injected cocktail of toxins is dominated by
CC       enzymes (mostly proteases S1 and chitiniases) and that it includes this
CC       probable paralytic neurotoxin. {ECO:0000269|PubMed:24132120}.
CC   -!- WEB RESOURCE: Name=National Center for Biotechnology Information
CC       (NCBI);
CC       URL="https://www.ncbi.nlm.nih.gov/sra/SRX282054";
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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   CDD; cd12960; Spider_toxin; 1.
DR   InterPro; IPR004169; Spidertoxin.
DR   Pfam; PF02819; Toxin_9; 1.
PE   2: Evidence at transcript level;
KW   Amidation; Disulfide bond; Ion channel impairing toxin; Knottin;
KW   Neurotoxin; Secreted; Signal; Toxin.
FT   SIGNAL          1..27
FT                   /evidence="ECO:0000255"
FT   PROPEP          28..31
FT                   /evidence="ECO:0000305|PubMed:24132120"
FT                   /id="PRO_0000454100"
FT   CHAIN           32..76
FT                   /note="Putative neurotoxin"
FT                   /evidence="ECO:0000305|PubMed:24132120"
FT                   /id="PRO_0000454101"
FT   MOD_RES         76
FT                   /note="Serine amide"
FT                   /evidence="ECO:0000305"
FT   DISULFID        34..49
FT                   /evidence="ECO:0000250|UniProtKB:B3EWH0"
FT   DISULFID        41..54
FT                   /evidence="ECO:0000250|UniProtKB:B3EWH0"
FT   DISULFID        48..65
FT                   /evidence="ECO:0000250|UniProtKB:B3EWH0"
FT   DISULFID        56..63
FT                   /evidence="ECO:0000250|UniProtKB:B3EWH0"
SQ   SEQUENCE   78 AA;  8848 MW;  D8166865835E9079 CRC64;
     MKEANTRRYI HLCLVVVLVS TIITTEAEDD RLFCIRHHKY CGHRPNRCCS GLFCRCNTFG
     TNCRCQSKGA LGKLISGK