ID   MKTX3_MESMA             Reviewed;          85 AA.
AC   P59853;
DT   19-SEP-2003, integrated into UniProtKB/Swiss-Prot.
DT   19-SEP-2003, sequence version 1.
DT   03-AUG-2022, entry version 66.
DE   RecName: Full=Makatoxin-3;
DE   AltName: Full=Makatoxin III;
DE            Short=MKTXIII;
DE            Short=MakatxIII;
DE            Short=MkTx III;
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=10978740; DOI=10.1016/s0041-0101(00)00119-7;
RA   Zeng X.-C., Li W.-X., Zhu S.-Y., Peng F., Zhu Z.-H., Liu H., Mao X.;
RT   "Molecular cloning and sequence analysis of cDNAs encoding a beta-toxin-
RT   like peptide and two MkTx I homologues from scorpion Buthus martensii
RT   Karsch.";
RL   Toxicon 39:225-232(2001).
CC   -!- FUNCTION: This protein markedly relaxes the rat carbachol-precontracted
CC       anococcygeus muscle. This relaxation is inhibited by the inhibitor of
CC       nitric oxide (NO) synthase, N-nitro-L-arginine methyl ester (L-NAME),
CC       suggesting that the response induced by this protein is NO-mediated (By
CC       similarity). {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250}.
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   AlphaFoldDB; P59853; -.
DR   SMR; P59853; -.
DR   TCDB; 8.B.1.1.2; the long (4c-c) scorpion toxin (l-st) superfamily.
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   2: Evidence at transcript level;
KW   Disulfide bond; Neurotoxin; Secreted; Signal; Toxin.
FT   SIGNAL          1..19
FT                   /evidence="ECO:0000250"
FT   CHAIN           20..83
FT                   /note="Makatoxin-3"
FT                   /id="PRO_0000035261"
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"
SQ   SEQUENCE   85 AA;  9434 MW;  14956BCDCEBAB640 CRC64;
     MNYLIVISFA LLLMTGVESG RDAYIAKKEN CTYFCALNPY CNDLCTKNGA KSGYCQWAGR
     YGNACWCIDL PDKVPIRIPG PCIGR