SIX1_MESMA
ID SIX1_MESMA Reviewed; 88 AA.
AC O61668; O61995;
DT 15-DEC-1998, integrated into UniProtKB/Swiss-Prot.
DT 01-AUG-1998, sequence version 1.
DT 25-MAY-2022, entry version 99.
DE RecName: Full=Beta-insect excitatory toxin BmKIT1;
DE AltName: Full=Bm32-VI {ECO:0000303|PubMed:11042276};
DE AltName: Full=BmK IT1 {ECO:0000303|PubMed:10078863};
DE Short=BmK IT {ECO:0000303|PubMed:8068186, ECO:0000312|EMBL:AAC14130.1};
DE Short=BmKIT {ECO:0000312|EMBL:CAA76604.1};
DE AltName: Full=BmK-betaIT;
DE Flags: Precursor;
OS Mesobuthus martensii (Manchurian scorpion) (Buthus martensii).
OC Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC Scorpiones; Buthida; Buthoidea; Buthidae; Mesobuthus.
OX NCBI_TaxID=34649;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA].
RC TISSUE=Venom gland;
RX PubMed=10078863; DOI=10.1016/s0041-0101(98)00176-7;
RA Xiong Y.-M., Ling M.-H., Lan Z.-D., Wang D.-C., Chi C.-W.;
RT "The cDNA sequence of an excitatory insect selective neurotoxin from the
RT scorpion Buthus martensi Karsch.";
RL Toxicon 37:335-341(1999).
RN [2]
RP PROTEIN SEQUENCE OF 19-88, AND SUBCELLULAR LOCATION.
RX PubMed=8068186;
RA Ji Y.H., Mansuelle P., Xu K., Granier C., Kopeyan C., Terakawa S.,
RA Rochat H.;
RT "Amino acid sequence of an excitatory insect-selective toxin (BmK IT) from
RT venom of the scorpion Buthus martensi Karsch.";
RL Sci. China, Ser. B, Chem. Life Sci. Earth Sci. 37:42-49(1994).
RN [3]
RP PROTEIN SEQUENCE OF 19-88, AMIDATION AT ILE-87, FUNCTION, TOXIC DOSE, AND
RP MASS SPECTROMETRY.
RC TISSUE=Venom;
RX PubMed=11042276; DOI=10.1016/s0014-5793(00)02099-8;
RA Escoubas P., Stankiewicz M., Takaoka T., Pelhate M., Romi-Lebrun R.,
RA Wu F.Q., Nakajima T.;
RT "Sequence and electrophysiological characterization of two insect-selective
RT excitatory toxins from the venom of the Chinese scorpion Buthus martensi.";
RL FEBS Lett. 483:175-180(2000).
RN [4]
RP NUCLEOTIDE SEQUENCE [MRNA] OF 19-88.
RA Liang A.H., Li X.L., Su Z.G., Wang W.;
RT "Cloning and sequencing of an excitatory insect-selective neurotoxin BmKIT
RT cDNA from Buthus martensii Karsch.";
RL Submitted (MAR-1998) to the EMBL/GenBank/DDBJ databases.
RN [5]
RP PROTEIN SEQUENCE OF 19-32, STRUCTURE BY NMR OF 19-87, DISULFIDE BONDS, AND
RP MASS SPECTROMETRY.
RC TISSUE=Venom;
RX PubMed=16970911; DOI=10.1016/j.bbrc.2006.08.131;
RA Tong X., Yao J., He F., Chen X., Zheng X., Xie C., Wu G., Zhang N.,
RA Ding J., Wu H.;
RT "NMR solution structure of BmK-betaIT, an excitatory scorpion beta-toxin
RT without a 'hot spot' at the relevant position.";
RL Biochem. Biophys. Res. Commun. 349:890-899(2006).
CC -!- FUNCTION: Excitatory insect beta-toxins induce a spastic paralysis.
CC They bind voltage-independently at site-4 of sodium channels (Nav) and
CC shift 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 {ECO:0000269|PubMed:11042276}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:8068186}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC {ECO:0000305|PubMed:8068186}.
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=7632.83; Method=MALDI;
CC Evidence={ECO:0000269|PubMed:11042276};
CC -!- MASS SPECTROMETRY: Mass=7634.0; Method=Electrospray;
CC Evidence={ECO:0000269|PubMed:16970911};
CC -!- TOXIC DOSE: PD(50) is 0.18 ng/mg of Gryllus bimaculatus crickets.
CC {ECO:0000269|PubMed:11042276}.
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; AF057555; AAC14130.1; -; mRNA.
DR EMBL; Y17050; CAA76604.1; -; mRNA.
DR PDB; 1WWN; NMR; -; A=19-87.
DR PDBsum; 1WWN; -.
DR AlphaFoldDB; O61668; -.
DR SMR; O61668; -.
DR TCDB; 8.B.1.1.5; the long (4c-c) scorpion toxin (l-st) superfamily.
DR EvolutionaryTrace; O61668; -.
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; IPR002061; Scorpion_toxinL/defensin.
DR Pfam; PF00537; Toxin_3; 1.
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; 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..18
FT /evidence="ECO:0000269|PubMed:11042276,
FT ECO:0000269|PubMed:8068186"
FT CHAIN 19..87
FT /note="Beta-insect excitatory toxin BmKIT1"
FT /evidence="ECO:0000269|PubMed:11042276,
FT ECO:0000269|PubMed:8068186"
FT /id="PRO_0000035200"
FT DOMAIN 20..83
FT /note="LCN-type CS-alpha/beta"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT MOD_RES 87
FT /note="Isoleucine amide"
FT /evidence="ECO:0000305|PubMed:11042276"
FT DISULFID 34..55
FT /evidence="ECO:0000269|PubMed:16970911,
FT ECO:0007744|PDB:1WWN"
FT DISULFID 40..60
FT /evidence="ECO:0000269|PubMed:16970911,
FT ECO:0007744|PDB:1WWN"
FT DISULFID 44..62
FT /evidence="ECO:0000269|PubMed:16970911,
FT ECO:0007744|PDB:1WWN"
FT DISULFID 56..82
FT /evidence="ECO:0000269|PubMed:16970911,
FT ECO:0007744|PDB:1WWN"
FT CONFLICT 87
FT /note="I -> N (in Ref. 4; CAA76604)"
FT /evidence="ECO:0000305"
FT STRAND 21..23
FT /evidence="ECO:0007829|PDB:1WWN"
FT STRAND 25..29
FT /evidence="ECO:0007829|PDB:1WWN"
FT HELIX 37..46
FT /evidence="ECO:0007829|PDB:1WWN"
FT STRAND 51..56
FT /evidence="ECO:0007829|PDB:1WWN"
FT STRAND 59..63
FT /evidence="ECO:0007829|PDB:1WWN"
FT HELIX 76..81
FT /evidence="ECO:0007829|PDB:1WWN"
FT TURN 82..86
FT /evidence="ECO:0007829|PDB:1WWN"
SQ SEQUENCE 88 AA; 9767 MW; 0170D30BDCE777B4 CRC64;
MKFFLIFLVI FPIMGVLGKK NGYAVDSSGK VSECLLNNYC NNICTKVYYA TSGYCCLLSC
YCFGLDDDKA VLKIKDATKS YCDVQIIG
