SIXE_HOTJU
ID SIXE_HOTJU Reviewed; 94 AA.
AC P56637;
DT 15-DEC-1998, integrated into UniProtKB/Swiss-Prot.
DT 15-DEC-1998, sequence version 1.
DT 25-MAY-2022, entry version 108.
DE RecName: Full=Beta-insect excitatory toxin Bj-xtrIT {ECO:0000303|PubMed:9753689};
DE Short=Bj-xtrIT {ECO:0000303|PubMed:10026198};
DE Short=Bjxtr-IT;
DE Short=BjxtrIT;
DE Flags: Precursor;
OS Hottentotta judaicus (Black scorpion) (Buthotus judaicus).
OC Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC Scorpiones; Buthida; Buthoidea; Buthidae; Hottentotta.
OX NCBI_TaxID=6863;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], X-RAY CRYSTALLOGRAPHY (2.1 ANGSTROMS) OF 19-94,
RP RECOMBINANT EXPRESSION, AND DISULFIDE BONDS.
RX PubMed=9753689; DOI=10.1016/s0969-2126(98)00111-7;
RA Oren D.A., Froy O., Amit E., Kleinberger-Doron N., Gurevitz M., Shaanan B.;
RT "An excitatory scorpion toxin with a distinctive feature: an additional
RT alpha helix at the C-terminus and its implications for interaction with
RT insect sodium channels.";
RL Structure 6:1095-1103(1998).
RN [2]
RP PROTEIN SEQUENCE OF 19-48, MASS SPECTROMETRY, TOXIC DOSE, MUTAGENESIS, AND
RP SUBCELLULAR LOCATION.
RC TISSUE=Venom;
RX PubMed=10026198; DOI=10.1074/jbc.274.9.5769;
RA Froy O., Zilberberg N., Gordon D., Turkov M., Gilles N., Stankiewicz M.,
RA Pelhate M., Loret E., Oren D.A., Shaanan B., Gurevitz M.;
RT "The putative bioactive surface of insect-selective scorpion excitatory
RT neurotoxins.";
RL J. Biol. Chem. 274:5769-5776(1999).
RN [3]
RP SYNTHESIS OF 19-94, AND MUTAGENESIS.
RX PubMed=14672947; DOI=10.1074/jbc.m307531200;
RA Cohen L., Karbat I., Gilles N., Froy O., Corzo G., Angelovici R.,
RA Gordon D., Gurevitz M.;
RT "Dissection of the functional surface of an anti-insect excitatory toxin
RT illuminates a putative 'hot spot' common to all scorpion beta-toxins
RT affecting Na+ channels.";
RL J. Biol. Chem. 279:8206-8211(2004).
RN [4]
RP SYNTHESIS OF 19-94, MUTAGENESIS OF LYS-19; LYS-20; ASP-26; LYS-30; GLU-33;
RP GLU-48; LYS-51; GLU-56; 71-GLU--ASP-73; ASP-72; LYS-74; ASP-81; LYS-84;
RP LYS-85 AND ASP-88, AND SITE.
RX PubMed=15054090; DOI=10.1096/fj.03-0733com;
RA Karbat I., Cohen L., Gilles N., Gordon D., Gurevitz M.;
RT "Conversion of a scorpion toxin agonist into an antagonist highlights an
RT acidic residue involved in voltage sensor trapping during activation of
RT neuronal Na+ channels.";
RL FASEB J. 18:683-689(2004).
RN [5]
RP ERRATUM OF PUBMED:15054090.
RA Karbat I., Cohen L., Gilles N., Gordon D., Gurevitz M.;
RL FASEB J. 18:947-947(2004).
RN [6]
RP X-RAY CRYSTALLOGRAPHY (1.7 ANGSTROMS) OF 19-94, DISULFIDE BONDS, AND
RP RECOMBINANT EXPRESSION.
RX PubMed=23999087; DOI=10.1016/j.bbagen.2013.08.021;
RA O'Reilly A.O., Cole A.R., Lopes J.L., Lampert A., Wallace B.A.;
RT "Chaperone-mediated native folding of a beta-scorpion toxin in the
RT periplasm of Escherichia coli.";
RL Biochim. Biophys. Acta 1840:10-15(2014).
CC -!- FUNCTION: Excitatory insect toxins induce a spastic paralysis. They
CC bind voltage-independently at site-4 of sodium channels (Nav) and shift
CC the voltage of activation toward more negative potentials thereby
CC affecting sodium channel activation and promoting spontaneous and
CC repetitive firing. This toxin is active only on insects.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:10026198}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC {ECO:0000305|PubMed:10026198}.
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=8455; Method=Unknown;
CC Evidence={ECO:0000269|PubMed:10026198};
CC -!- TOXIC DOSE: Both variants Bjxtr-IT.56E and Bjxtr-IT.56K have an PD(50)
CC of 9.6 ng/100 mg of body weight of blowfly larvae.
CC {ECO:0000269|PubMed:10026198}.
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; AJ012312; CAA09987.1; -; mRNA.
DR EMBL; AJ012313; CAA09988.1; -; mRNA.
DR PDB; 1BCG; X-ray; 2.10 A; A=19-94.
DR PDB; 4KYP; X-ray; 1.70 A; A/B/C/D=19-94.
DR PDBsum; 1BCG; -.
DR PDBsum; 4KYP; -.
DR AlphaFoldDB; P56637; -.
DR SMR; P56637; -.
DR EvolutionaryTrace; P56637; -.
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 Gene3D; 3.30.30.10; -; 1.
DR InterPro; IPR044062; LCN-type_CS_alpha_beta_dom.
DR InterPro; IPR036574; Scorpion_toxin-like_sf.
DR InterPro; IPR002061; Scorpion_toxinL/defensin.
DR Pfam; PF00537; Toxin_3; 1.
DR SUPFAM; SSF57095; SSF57095; 1.
DR PROSITE; PS51863; LCN_CSAB; 1.
PE 1: Evidence at protein level;
KW 3D-structure; Direct protein sequencing; Disulfide bond;
KW Ion channel impairing toxin; Neurotoxin; Secreted; Signal; Toxin;
KW Voltage-gated sodium channel impairing toxin.
FT SIGNAL 1..18
FT /evidence="ECO:0000269|PubMed:10026198"
FT CHAIN 19..94
FT /note="Beta-insect excitatory toxin Bj-xtrIT"
FT /evidence="ECO:0000305|PubMed:10026198"
FT /id="PRO_0000035199"
FT DOMAIN 20..88
FT /note="LCN-type CS-alpha/beta"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT SITE 33
FT /note="May be involved in voltage sensor trapping upon
FT activation of sodium channel"
FT SITE 48
FT /note="May interact with a positively charged residue of
FT the receptor site"
FT DISULFID 34..60
FT /evidence="ECO:0000269|PubMed:23999087,
FT ECO:0000269|PubMed:9753689, ECO:0007744|PDB:1BCG,
FT ECO:0007744|PDB:4KYP"
FT DISULFID 45..65
FT /evidence="ECO:0000269|PubMed:23999087,
FT ECO:0000269|PubMed:9753689, ECO:0007744|PDB:1BCG,
FT ECO:0007744|PDB:4KYP"
FT DISULFID 49..67
FT /evidence="ECO:0000269|PubMed:23999087,
FT ECO:0000269|PubMed:9753689, ECO:0007744|PDB:1BCG,
FT ECO:0007744|PDB:4KYP"
FT DISULFID 61..87
FT /evidence="ECO:0000269|PubMed:23999087,
FT ECO:0000269|PubMed:9753689, ECO:0007744|PDB:1BCG,
FT ECO:0007744|PDB:4KYP"
FT VARIANT 56
FT /note="E -> K"
FT MUTAGEN 19
FT /note="K->A: Little effect on toxicity and on the binding
FT affinity."
FT /evidence="ECO:0000269|PubMed:15054090"
FT MUTAGEN 20
FT /note="K->A: Little effect on toxicity and on the binding
FT affinity."
FT /evidence="ECO:0000269|PubMed:15054090"
FT MUTAGEN 26
FT /note="D->A: Little effect on toxicity and on the binding
FT affinity."
FT /evidence="ECO:0000269|PubMed:15054090"
FT MUTAGEN 30
FT /note="K->A: Little effect on toxicity and on the binding
FT affinity."
FT /evidence="ECO:0000269|PubMed:15054090"
FT MUTAGEN 33
FT /note="E->A: 47.5-fold decrease in toxicity and little
FT effect on the binding affinity."
FT /evidence="ECO:0000269|PubMed:15054090"
FT MUTAGEN 33
FT /note="E->F: 743-fold decrease in toxicity and little
FT effect on the binding affinity."
FT /evidence="ECO:0000269|PubMed:15054090"
FT MUTAGEN 33
FT /note="E->R: >10000-fold decrease in toxicity and little
FT decrease in binding affinity."
FT /evidence="ECO:0000269|PubMed:15054090"
FT MUTAGEN 48
FT /note="E->D: 8.3-fold decrease in toxicity and 43.6-fold
FT decrease in binding affinity."
FT /evidence="ECO:0000269|PubMed:15054090"
FT MUTAGEN 48
FT /note="E->L: 29-fold decrease in toxicity and 158-fold
FT decrease in binding affinity."
FT /evidence="ECO:0000269|PubMed:15054090"
FT MUTAGEN 48
FT /note="E->Q: 27.3-fold decrease in toxicity and 74.5-fold
FT decrease in binding affinity."
FT /evidence="ECO:0000269|PubMed:15054090"
FT MUTAGEN 48
FT /note="E->R: 608-fold decrease in toxicity and 11455-fold
FT decrease in binding affinity."
FT /evidence="ECO:0000269|PubMed:15054090"
FT MUTAGEN 51
FT /note="K->A: Little effect on toxicity and on the binding
FT affinity."
FT /evidence="ECO:0000269|PubMed:15054090"
FT MUTAGEN 56
FT /note="E->I: Little effect on toxicity and on the binding
FT affinity."
FT /evidence="ECO:0000269|PubMed:15054090"
FT MUTAGEN 71..73
FT /note="EDD->AAA: Little effect on toxicity and on the
FT binding affinity."
FT /evidence="ECO:0000269|PubMed:15054090"
FT MUTAGEN 71..73
FT /note="EDD->KRR: Little effect on toxicity and on the
FT binding affinity."
FT /evidence="ECO:0000269|PubMed:15054090"
FT MUTAGEN 72
FT /note="D->A: Little effect on toxicity and on the binding
FT affinity."
FT /evidence="ECO:0000269|PubMed:15054090"
FT MUTAGEN 73
FT /note="D->A: Little effect on toxicity and on the binding
FT affinity."
FT MUTAGEN 74
FT /note="K->T: Little effect on toxicity and on the binding
FT affinity."
FT /evidence="ECO:0000269|PubMed:15054090"
FT MUTAGEN 81
FT /note="D->N: Little effect on toxicity and on the binding
FT affinity."
FT /evidence="ECO:0000269|PubMed:15054090"
FT MUTAGEN 84
FT /note="K->A: Little effect on toxicity and on the binding
FT affinity."
FT /evidence="ECO:0000269|PubMed:15054090"
FT MUTAGEN 85
FT /note="K->A: Little effect on toxicity and on the binding
FT affinity."
FT /evidence="ECO:0000269|PubMed:15054090"
FT MUTAGEN 88
FT /note="D->A: Little effect on toxicity and on the binding
FT affinity."
FT /evidence="ECO:0000269|PubMed:15054090"
FT MUTAGEN 93..94
FT /note="Missing: 4.6-fold reduction of toxicity."
FT MUTAGEN 94
FT /note="Missing: 5.7-fold reduction of toxicity."
FT STRAND 20..22
FT /evidence="ECO:0007829|PDB:4KYP"
FT HELIX 37..40
FT /evidence="ECO:0007829|PDB:4KYP"
FT HELIX 43..51
FT /evidence="ECO:0007829|PDB:4KYP"
FT STRAND 56..61
FT /evidence="ECO:0007829|PDB:4KYP"
FT STRAND 64..70
FT /evidence="ECO:0007829|PDB:4KYP"
FT HELIX 81..89
FT /evidence="ECO:0007829|PDB:4KYP"
SQ SEQUENCE 94 AA; 10512 MW; 40F6510F26E4BB90 CRC64;
MKFFLMCLII FPIMGVLGKK NGYPLDRNGK TTECSGVNAI APHYCNSECT KVYYAESGYC
CWGACYCFGL EDDKPIGPMK DITKKYCDVQ IIPS
