SC12_MESMA
ID SC12_MESMA Reviewed; 85 AA.
AC Q9GQW3;
DT 19-DEC-2001, integrated into UniProtKB/Swiss-Prot.
DT 01-MAR-2001, sequence version 1.
DT 03-AUG-2022, entry version 91.
DE RecName: Full=Toxin BmKaIT1;
DE Short=BmKalphaIT1;
DE AltName: Full=Alpha-neurotoxin IT01;
DE AltName: Full=Alpha-neurotoxin TX12;
DE AltName: Full=BmKalphaIT01;
DE AltName: Full=BmKalphaTx12;
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=10858508; DOI=10.1016/s0041-0101(00)00081-7;
RA Zhu S.-Y., Li W.-X., Zeng X.-C., Liu H., Jiang D.-H., Mao X.;
RT "Nine novel precursors of Buthus martensii scorpion alpha-toxin
RT homologues.";
RL Toxicon 38:1653-1661(2000).
RN [2]
RP SEQUENCE REVISION, X-RAY CRYSTALLOGRAPHY (2.0 ANGSTROMS) OF 20-83, AND
RP DISULFIDE BONDS.
RX PubMed=12925796; DOI=10.1107/s090744490301415x;
RA Huang Y., Huang Q., Chen H., Tang Y., Miyake H., Kusunoki M.;
RT "Crystallization and preliminary crystallographic study of rBmKalphaIT1, a
RT recombinant alpha-insect toxin from the scorpion Buthus martensii Karsch.";
RL Acta Crystallogr. D 59:1635-1636(2003).
RN [3]
RP FUNCTION.
RA Wu H., Wu G., Huang X.L., He F., Jiang S.K.;
RT "Purification, characterization and structural study of the neuropeptides
RT from scorpion Buthus martensii Karsch.";
RL Pure Appl. Chem. 71:1157-1162(1999).
RN [4]
RP FUNCTION.
RA Wu H., Wu G., He F., Jiang S.K.;
RT "A new insect-specific toxin from the venom of scorpion Buthus martensii
RT Karsch.";
RL Prog. Nat. Sci. 9:631-634(1999).
RN [5]
RP STRUCTURE BY NMR OF 20-83, AND DISULFIDE BONDS.
RX PubMed=17877370; DOI=10.1021/bi7006788;
RA Tong X., Zhu J., Ma Y., Chen X., Wu G., He F., Cao C., Wu H.;
RT "Solution structure of BmKalphaIT01, an alpha-insect toxin from the venom
RT of the Chinese scorpion Buthus martensii Karsch.";
RL Biochemistry 46:11322-11330(2007).
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 (By similarity). Shows a high
CC toxicity toward insects and moderate toxicity against mammals.
CC {ECO:0000250, ECO:0000269|Ref.3, ECO:0000269|Ref.4}.
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 -!- MISCELLANEOUS: Exists in two forms, due to cis-trans isomerization at
CC 28-Asn-Tyr-29. Adopts a predominately cis conformation.
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 EMBL; AF151796; AAG39640.1; -; mRNA.
DR PDB; 1OMY; X-ray; 2.00 A; A=20-83.
DR PDB; 2E0H; NMR; -; A=20-83.
DR PDBsum; 1OMY; -.
DR PDBsum; 2E0H; -.
DR AlphaFoldDB; Q9GQW3; -.
DR BMRB; Q9GQW3; -.
DR SMR; Q9GQW3; -.
DR EvolutionaryTrace; Q9GQW3; -.
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 3D-structure; Disulfide bond; Ion channel impairing toxin; Neurotoxin;
KW Secreted; Signal; Toxin; Voltage-gated sodium channel impairing toxin.
FT SIGNAL 1..19
FT CHAIN 20..83
FT /note="Toxin BmKaIT1"
FT /id="PRO_0000035246"
FT PROPEP 84..85
FT /note="Removed by a carboxypeptidase"
FT /evidence="ECO:0000305"
FT /id="PRO_0000035247"
FT DOMAIN 21..83
FT /note="LCN-type CS-alpha/beta"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 31..82
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 35..55
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 41..65
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT DISULFID 45..67
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT STRAND 21..27
FT /evidence="ECO:0007829|PDB:1OMY"
FT TURN 28..30
FT /evidence="ECO:0007829|PDB:1OMY"
FT HELIX 38..46
FT /evidence="ECO:0007829|PDB:1OMY"
FT TURN 47..49
FT /evidence="ECO:0007829|PDB:1OMY"
FT STRAND 51..54
FT /evidence="ECO:0007829|PDB:1OMY"
FT STRAND 57..64
FT /evidence="ECO:0007829|PDB:1OMY"
FT STRAND 66..70
FT /evidence="ECO:0007829|PDB:1OMY"
SQ SEQUENCE 85 AA; 9649 MW; 79C040C18F20057F CRC64;
MNYLVMISFA FLLMTGVESV RDAYIAQNYN CVYHCARDAY CNELCTKNGA KSGSCPYLGE
HKFACYCKDL PDNVPIRVPG KCHRR
