SCX5_CENNO
ID SCX5_CENNO Reviewed; 87 AA.
AC P45663;
DT 01-NOV-1995, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1995, sequence version 1.
DT 03-AUG-2022, entry version 91.
DE RecName: Full=Beta-toxin Cn5;
DE AltName: Full=CngtII;
DE Flags: Precursor;
OS Centruroides noxius (Mexican scorpion).
OC Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC Scorpiones; Buthida; Buthoidea; Buthidae; Centruroides.
OX NCBI_TaxID=6878;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA].
RC TISSUE=Venom gland;
RX PubMed=8390386; DOI=10.1016/0378-1119(93)90559-l;
RA Becerril B., Vazquez A., Garcia C., Corona M., Bolivar F., Possani L.D.;
RT "Cloning and characterization of cDNAs that code for Na(+)-channel-blocking
RT toxins of the scorpion Centruroides noxius Hoffmann.";
RL Gene 128:165-171(1993).
RN [2]
RP PROTEIN SEQUENCE OF 20-85, AND DISULFIDE BONDS.
RC TISSUE=Venom;
RX PubMed=9114491; DOI=10.1016/s0305-0491(96)00246-5;
RA Garcia C., Becerril B., Selisko B., Delepierre M., Possani L.D.;
RT "Isolation, characterization and comparison of a novel crustacean toxin
RT with a mammalian toxin from the venom of the scorpion Centruroides noxius
RT Hoffmann.";
RL Comp. Biochem. Physiol. 116B:315-322(1997).
RN [3]
RP NUCLEOTIDE SEQUENCE [MRNA] OF 20-85, PROTEIN SEQUENCE OF 20-85, STRUCTURE
RP BY NMR OF 20-85, FUNCTION, SUBCELLULAR LOCATION, TISSUE SPECIFICITY, MASS
RP SPECTROMETRY, TOXIC DOSE, AND DISULFIDE BONDS.
RC TISSUE=Venom, and Venom gland;
RX PubMed=19631296; DOI=10.1016/j.bbapap.2009.07.006;
RA Corzo G., Prochnicka-Chalufour A., Garcia B.I., Possani L.D.,
RA Delepierre M.;
RT "Solution structure of Cn5, a crustacean toxin found in the venom of the
RT scorpions Centruroides noxius and Centruroides suffusus suffusus.";
RL Biochim. Biophys. Acta 1794:1591-1598(2009).
CC -!- FUNCTION: Beta toxins bind voltage-independently at site-4 of sodium
CC channels (Nav) and shift the voltage of activation toward more negative
CC potentials thereby affecting sodium channel activation and promoting
CC spontaneous and repetitive firing. This toxin is lethal to crustaceans
CC (freshwater crayfish (Cambarellus montezumae spp.)), it provokes a
CC reversible paralysis to insects (crickets (Achaeta spp.)), but is not
CC toxic to mice. At high concentrations, it does displace the (beta)
CC mammal-specific toxin Cn2 from rat brain synaptosomes.
CC {ECO:0000269|PubMed:19631296}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:19631296}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC {ECO:0000269|PubMed:19631296}.
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=7136.0; Method=Electrospray;
CC Evidence={ECO:0000269|PubMed:19631296};
CC -!- TOXIC DOSE: LD(50) is 28.5 mg/g body weight of crayfish.
CC {ECO:0000269|PubMed:19631296}.
CC -!- SIMILARITY: Belongs to the long (4 C-C) scorpion toxin superfamily.
CC Sodium channel inhibitor family. Beta subfamily. {ECO:0000305}.
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DR EMBL; L05060; AAA28285.1; -; mRNA.
DR PIR; JN0669; JN0669.
DR PDB; 2KJA; NMR; -; A=20-85.
DR PDBsum; 2KJA; -.
DR AlphaFoldDB; P45663; -.
DR SMR; P45663; -.
DR EvolutionaryTrace; P45663; -.
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 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 3D-structure; Cleavage on pair of basic residues;
KW Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW Neurotoxin; Secreted; Signal; Toxin;
KW Voltage-gated sodium channel impairing toxin.
FT SIGNAL 1..19
FT /evidence="ECO:0000269|PubMed:19631296,
FT ECO:0000269|PubMed:9114491"
FT CHAIN 20..85
FT /note="Beta-toxin Cn5"
FT /id="PRO_0000035282"
FT DOMAIN 20..85
FT /note="LCN-type CS-alpha/beta"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 31..84
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 35..60
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 44..65
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 48..67
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT TURN 27..29
FT /evidence="ECO:0007829|PDB:2KJA"
FT HELIX 42..48
FT /evidence="ECO:0007829|PDB:2KJA"
FT TURN 51..53
FT /evidence="ECO:0007829|PDB:2KJA"
FT STRAND 56..61
FT /evidence="ECO:0007829|PDB:2KJA"
FT STRAND 64..68
FT /evidence="ECO:0007829|PDB:2KJA"
FT STRAND 72..74
FT /evidence="ECO:0007829|PDB:2KJA"
SQ SEQUENCE 87 AA; 9480 MW; 867E459B95064A87 CRC64;
MNSLLMITAC LFLIGTVWAK EGYLVNKSTG CKYGCLLLGK NEGCDKECKA KNQGGSYGYC
YAFGCWCEGL PESTPTYPLP NKSCSKK
