ID   SCX4_LEIQU              Reviewed;          65 AA.
AC   P01489;
DT   21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT   21-JUL-1986, sequence version 1.
DT   03-AUG-2022, entry version 93.
DE   RecName: Full=Alpha-toxin Lqq4;
DE   AltName: Full=Lqq IV;
DE            Short=LqqIV;
DE   AltName: Full=Toxin IV;
OS   Leiurus quinquestriatus quinquestriatus (Egyptian scorpion) (Deathstalker
OS   scorpion).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Leiurus.
OX   NCBI_TaxID=6885;
RN   [1]
RP   PROTEIN SEQUENCE, AND AMIDATION AT ARG-65.
RA   Kopeyan C., Martinez G., Rochat H.;
RT   "Primary structure of toxin IV of Leiurus quinquestriatus
RT   quinquestriatus.";
RL   FEBS Lett. 181:211-217(1985).
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.
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   -!- SIMILARITY: Belongs to the long (4 C-C) scorpion toxin superfamily.
CC       Sodium channel inhibitor family. Alpha subfamily. {ECO:0000305}.
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DR   PIR; A01749; NTSR4L.
DR   AlphaFoldDB; P01489; -.
DR   SMR; P01489; -.
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   Amidation; Direct protein sequencing; Disulfide bond;
KW   Ion channel impairing toxin; Neurotoxin; Secreted; Toxin;
KW   Voltage-gated sodium channel impairing toxin.
FT   CHAIN           1..65
FT                   /note="Alpha-toxin Lqq4"
FT                   /id="PRO_0000066781"
FT   DOMAIN          3..65
FT                   /note="LCN-type CS-alpha/beta"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   MOD_RES         65
FT                   /note="Arginine amide"
FT                   /evidence="ECO:0000269|Ref.1"
FT   DISULFID        13..64
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        17..37
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        23..47
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        27..49
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
SQ   SEQUENCE   65 AA;  7202 MW;  882102EC1C2B89F6 CRC64;
     GVRDAYIADD KNCVYTCGSN SYCNTECTKN GAESGYCQWL GKYGNACWCI KLPDKVPIRI
     PGKCR