SCX5B_MESEU
ID SCX5B_MESEU Reviewed; 87 AA.
AC E7D082;
DT 03-JUL-2019, integrated into UniProtKB/Swiss-Prot.
DT 08-MAR-2011, sequence version 1.
DT 03-AUG-2022, entry version 45.
DE RecName: Full=Sodium channel neurotoxin MeuNaTxalpha-5* {ECO:0000303|PubMed:21969612};
DE AltName: Full=MeuNaTxalpha-5b {ECO:0000312|EMBL:ADU05410.1, ECO:0000312|EMBL:AEM44794.1};
DE Flags: Precursor;
OS Mesobuthus eupeus (Lesser Asian scorpion) (Buthus eupeus).
OC Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC Scorpiones; Buthida; Buthoidea; Buthidae; Mesobuthus.
OX NCBI_TaxID=34648;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA / MRNA], PROTEIN SEQUENCE OF 20-39,
RP STRUCTURE BY NMR OF 20-85, FUNCTION, SUBCELLULAR LOCATION, AND MASS
RP SPECTROMETRY.
RC TISSUE=Venom, and Venom gland;
RX PubMed=21969612; DOI=10.1074/mcp.m111.012054;
RA Zhu S., Peigneur S., Gao B., Lu X., Cao C., Tytgat J.;
RT "Evolutionary diversification of Mesobuthus alpha-scorpion toxins affecting
RT sodium channels.";
RL Mol. Cell. Proteomics 11:M111.012054-M111.012054(2012).
RN [2]
RP PROTEIN SEQUENCE OF 20-85, FUNCTION, SUBCELLULAR LOCATION, AND MASS
RP SPECTROMETRY.
RC TISSUE=Venom;
RA Zhu S.Y., Gao B.;
RT "Characterization of a sodium channel toxin from the scorpion Mesobuthus
RT eupeus venom.";
RL Submitted (NOV-2009) to UniProtKB.
CC -!- FUNCTION: Alpha toxins bind voltage-independently at site-3 of sodium
CC channels (Nav) and inhibit the inactivation of the activated channels,
CC thereby blocking neuronal transmission. This toxin inhibits
CC inactivation of Nav1.6/SCN8A (EC(50)=790 nM) and drosophila DmNav1
CC (EC(50)=280 nM) (PubMed:21969612, Ref.2). The toxin (1 uM) does not
CC significantly shift the midpoint of activation at the two channels, but
CC induces a significant depolarizing shift in the V(1/2) of inactivation
CC of the channels (PubMed:21969612). Has antimicrobial activity (Ref.2).
CC {ECO:0000269|PubMed:21969612, ECO:0000269|Ref.2}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:21969612,
CC ECO:0000269|Ref.2}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC {ECO:0000305|PubMed:21969612, ECO:0000305|Ref.2}.
CC -!- DOMAIN: Has the structural arrangement of an alpha-helix connected to
CC antiparallel beta-sheets by disulfide bonds (CS-alpha/beta).
CC {ECO:0000305}.
CC -!- MASS SPECTROMETRY: Mass=7170.47; Method=MALDI;
CC Evidence={ECO:0000269|PubMed:21969612};
CC -!- MISCELLANEOUS: Shows no effect on Nav1.2/SCN2A and Nav1.8/SCN10A
CC (PubMed:21969612). Shows a weak inhibition of inactivation on
CC Nav1.3/SCN3A, Nav1.4/SCN4A, Nav1.5/SCN5A, and Nav1.7/SCN9A.
CC {ECO:0000269|PubMed:21969612}.
CC -!- SIMILARITY: Belongs to the long (4 C-C) scorpion toxin superfamily.
CC Sodium channel inhibitor family. Alpha subfamily. {ECO:0000305}.
CC -!- CAUTION: Several genes are coding for this toxin for which the
CC structure by NMR has been determined. The cross-references to PDB and
CC additional information can be found in entry AC P86405. {ECO:0000305}.
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DR EMBL; HM992828; ADU05410.1; -; Genomic_DNA.
DR EMBL; HQ170506; AEM44794.1; -; mRNA.
DR AlphaFoldDB; E7D082; -.
DR SMR; E7D082; -.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0019871; F:sodium channel inhibitor activity; IEA:InterPro.
DR GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR GO; GO:0006952; P:defense response; IEA:InterPro.
DR CDD; cd00107; Knot1; 1.
DR Gene3D; 3.30.30.10; -; 1.
DR InterPro; IPR044062; LCN-type_CS_alpha_beta_dom.
DR InterPro; IPR003614; Scorpion_toxin-like.
DR InterPro; IPR036574; Scorpion_toxin-like_sf.
DR InterPro; IPR018218; Scorpion_toxinL.
DR InterPro; IPR002061; Scorpion_toxinL/defensin.
DR Pfam; PF00537; Toxin_3; 1.
DR PRINTS; PR00285; SCORPNTOXIN.
DR SMART; SM00505; Knot1; 1.
DR SUPFAM; SSF57095; SSF57095; 1.
DR PROSITE; PS51863; LCN_CSAB; 1.
PE 1: Evidence at protein level;
KW Antimicrobial; Direct protein sequencing; Disulfide bond;
KW Ion channel impairing toxin; Neurotoxin; Secreted; Signal; Toxin;
KW Voltage-gated sodium channel impairing toxin.
FT SIGNAL 1..19
FT /evidence="ECO:0000269|PubMed:21969612, ECO:0000269|Ref.2"
FT CHAIN 20..85
FT /note="Sodium channel neurotoxin MeuNaTxalpha-5*"
FT /evidence="ECO:0000269|Ref.2"
FT /id="PRO_5007654375"
FT PROPEP 86..87
FT /note="Removed by a carboxypeptidase"
FT /evidence="ECO:0000305"
FT /id="PRO_0000447446"
FT DOMAIN 21..85
FT /note="LCN-type CS-alpha/beta"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 31..84
FT /evidence="ECO:0000269|PubMed:21969612"
FT DISULFID 35..57
FT /evidence="ECO:0000269|PubMed:21969612"
FT DISULFID 43..67
FT /evidence="ECO:0000269|PubMed:21969612"
FT DISULFID 47..69
FT /evidence="ECO:0000269|PubMed:21969612"
SQ SEQUENCE 87 AA; 9570 MW; D2912D44396A8AE0 CRC64;
MNYLILISFA LLVITGVESA RDAYIAKPHN CVYECFDAFS SYCNGVCTKN GAKSGYCQIL
GTYGNGCWCI ALPDNVPIRI PGKCHRR
