SCX1_TITZU
ID SCX1_TITZU Reviewed; 86 AA.
AC Q2NME3; Q1I166;
DT 17-OCT-2006, integrated into UniProtKB/Swiss-Prot.
DT 07-FEB-2006, sequence version 1.
DT 03-AUG-2022, entry version 43.
DE RecName: Full=Beta-toxin Tz1;
DE AltName: Full=PT-beta NaTx14.1;
DE Flags: Precursor;
OS Tityus zulianus (Venezuelan scorpion).
OC Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC Scorpiones; Buthida; Buthoidea; Buthidae; Tityus.
OX NCBI_TaxID=288787;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 21-30, FUNCTION, EC(50),
RP AND MASS SPECTROMETRY.
RC TISSUE=Venom, and Venom gland;
RX PubMed=15109888; DOI=10.1016/j.toxicon.2004.02.022;
RA Borges A., Alfonzo M.J., Garcia C.C., Winand N.J., Leipold E.,
RA Heinemann S.H.;
RT "Isolation, molecular cloning and functional characterization of a novel
RT beta-toxin from the Venezuelan scorpion, Tityus zulianus.";
RL Toxicon 43:671-684(2004).
RN [2]
RP NUCLEOTIDE SEQUENCE [MRNA] OF 14-86, AND MASS SPECTROMETRY.
RC TISSUE=Venom, and Venom gland;
RX PubMed=16356783; DOI=10.1016/j.cbpc.2005.10.011;
RA Borges A., Garcia C.C., Lugo E., Alfonzo M.J., Jowers M.J.,
RA Op den Camp H.J.M.;
RT "Diversity of long-chain toxins in Tityus zulianus and Tityus discrepans
RT venoms (Scorpiones, Buthidae): molecular, immunological, and mass spectral
RT analyses.";
RL Comp. Biochem. Physiol. 142C:240-252(2006).
RN [3]
RP FUNCTION.
RX PubMed=16638971; DOI=10.1124/mol.106.024034;
RA Leipold E., Hansel A., Borges A., Heinemann S.H.;
RT "Subtype specificity of scorpion beta-toxin Tz1 interaction with voltage-
RT gated sodium channels is determined by the pore loop of domain 3.";
RL Mol. Pharmacol. 70:340-347(2006).
RN [4]
RP NOMENCLATURE.
RX PubMed=22355312; DOI=10.1371/journal.pone.0030478;
RA Guerrero-Vargas J.A., Mourao C.B., Quintero-Hernandez V., Possani L.D.,
RA Schwartz E.F.;
RT "Identification and phylogenetic analysis of Tityus pachyurus and Tityus
RT obscurus novel putative Na+-channel scorpion toxins.";
RL PLoS ONE 7:E30478-E30478(2012).
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. Strongly affects skeletal muscle
CC channels Nav1.4/SCN4A, poorly affects the neuronal channels
CC Nav1.6/SCN8A and Nav1.2/SCN2A. Induces spastic paralysis of rear limbs,
CC increased salivation, apnea, tachycardia and increased perspiration.
CC {ECO:0000269|PubMed:15109888, ECO:0000269|PubMed:16638971}.
CC -!- SUBCELLULAR LOCATION: Secreted.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
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=7367.16; Method=Electrospray;
CC Evidence={ECO:0000269|PubMed:15109888};
CC -!- MASS SPECTROMETRY: Mass=7366.45; Method=MALDI;
CC Evidence={ECO:0000269|PubMed:16356783};
CC -!- MISCELLANEOUS: Does not affect the cardiac Nav1.5/SCN5A, the peripheral
CC nerve channel Nav1.7/SCN9A, and the voltage-dependent potassium channel
CC Kv1.5/KCNA5. {ECO:0000305|PubMed:16638971}.
CC -!- MISCELLANEOUS: EC(50) is 3.5 uM.
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; AY874060; AAX58773.1; -; mRNA.
DR EMBL; DQ075235; AAZ29714.1; -; mRNA.
DR EMBL; DQ075236; AAZ29715.1; -; mRNA.
DR EMBL; DQ075238; AAZ29717.1; -; mRNA.
DR EMBL; DQ075240; AAZ29719.1; -; mRNA.
DR AlphaFoldDB; Q2NME3; -.
DR SMR; Q2NME3; -.
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 Amidation; Direct protein sequencing; Disulfide bond;
KW Ion channel impairing toxin; Neurotoxin; Secreted; Signal; Toxin;
KW Voltage-gated sodium channel impairing toxin.
FT SIGNAL 1..20
FT /evidence="ECO:0000269|PubMed:15109888"
FT CHAIN 21..84
FT /note="Beta-toxin Tz1"
FT /id="PRO_0000253776"
FT DOMAIN 21..83
FT /note="LCN-type CS-alpha/beta"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT MOD_RES 84
FT /note="Arginine amide"
FT /evidence="ECO:0000250"
FT DISULFID 31..82
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 35..57
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 43..63
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 47..65
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
SQ SEQUENCE 86 AA; 9915 MW; 546172BAB643B73A CRC64;
MTRFVLFICC FFLIGMVVEC KDGYLVGNDG CKYSCFTRPG TYCANECSRV KGKDGYCYAW
MACYCYSMPN WVKTWDRATN RCGRGK
