ID   MIT1_DENPO              Reviewed;          81 AA.
AC   P25687;
DT   01-MAY-1992, integrated into UniProtKB/Swiss-Prot.
DT   19-JUL-2005, sequence version 3.
DT   02-SEP-2026, entry version 95.
DE   RecName: Full=Toxin MIT1 {ECO:0000303|PubMed:10567694};
DE            Short=MIT 1 {ECO:0000303|PubMed:10567694};
DE   AltName: Full=Black mamba intestinal toxin 1 {ECO:0000303|PubMed:10567694};
DE   AltName: Full=Black mamba venom protein A {ECO:0000303|PubMed:7461607};
OS   Dendroaspis polylepis polylepis (Black mamba).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Elapidae; Elapinae; Dendroaspis.
OX   NCBI_TaxID=8620;
RN   [1]
RP   PROTEIN SEQUENCE, SEQUENCE REVISION TO 18; 22 AND 54, FUNCTION, AND
RP   SUBCELLULAR LOCATION.
RC   TISSUE=Venom;
RX   PubMed=10567694; DOI=10.1016/s0014-5793(99)01459-3;
RA   Schweitz H., Pascaud P., Diochot S., Moinier D., Lazdunski M.;
RT   "MIT1, a black mamba toxin with a new and highly potent activity on
RT   intestinal contraction.";
RL   FEBS Lett. 461:183-188(1999).
RN   [2]
RP   PROTEIN SEQUENCE OF 1-80.
RC   TISSUE=Venom;
RX   PubMed=7461607; DOI=10.1515/bchm2.1980.361.2.1787;
RA   Joubert F.J., Strydom D.J.;
RT   "Snake venom. The amino acid sequence of protein A from Dendroaspis
RT   polylepis polylepis (black mamba) venom.";
RL   Hoppe-Seyler's Z. Physiol. Chem. 361:1787-1794(1980).
RN   [3]
RP   PARTIAL PROTEIN SEQUENCE, FUNCTION, AND ACTIVITY PROFILE.
RC   TISSUE=Venom;
RX   PubMed=12054613; DOI=10.1016/s0006-291x(02)00239-5;
RA   Masuda Y., Takatsu Y., Terao Y., Kumano S., Ishibashi Y., Suenaga M.,
RA   Abe M., Fukusumi S., Watanabe T., Shintani Y., Yamada T., Hinuma S.,
RA   Inatomi N., Ohtaki T., Onda H., Fujino M.;
RT   "Isolation and identification of EG-VEGF/prokineticins as cognate ligands
RT   for two orphan G-protein-coupled receptors.";
RL   Biochem. Biophys. Res. Commun. 293:396-402(2002).
RN   [4]
RP   STRUCTURE BY NMR OF 1-80, AND DISULFIDE BONDS.
RC   TISSUE=Venom;
RX   PubMed=9761684; DOI=10.1006/jmbi.1998.2057;
RA   Boisbouvier J., Albrand J.-P., Blackledge M., Jaquinod M., Schweitz H.,
RA   Lazdunski M., Marion D.;
RT   "A structural homologue of colipase in black mamba venom revealed by NMR
RT   floating disulphide bridge analysis.";
RL   J. Mol. Biol. 283:205-219(1998).
CC   -!- FUNCTION: Potent agonist for both PKR1/PROKR1 and PKR2/PROKR2
CC       (PubMed:12054613). Potently contracts gastrointestinal (GI) smooth
CC       muscle (PubMed:10567694). {ECO:0000269|PubMed:10567694,
CC       ECO:0000269|PubMed:12054613}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:10567694}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:10567694}.
CC   -!- MISCELLANEOUS: Negative results: does not inhibit Kv1.1/KCNA1,
CC       Kv1.2/KCNA2, Kv1.3/KCNA3, Kv1.4/KCNA4, Kv1.5/KCNA5, Kv2.1/KCNB1,
CC       Kv3.4/KCNC4, Kv4.2/KCND2, K2P2.1/KCNK2, Kv11/KCNH, Kv7.1/KCNQ1,
CC       Kv7.2/KCNQ2, Kv7.3/KCNQ3, Kir1.1/KCNJ1, Kir2.1/KCNJ2, Kir2.2/KCNJ12,
CC       Kir3.1/KCNJ3-Kir3.2/KCNJ6 (GIRK1,2) and Kir3.1/KCNJ3-Kir3.4/KCNJ5
CC       (GIRK1,4). {ECO:0000269|PubMed:10567694}.
CC   -!- SIMILARITY: Belongs to the AVIT (prokineticin) family. {ECO:0000305}.
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DR   PDB; 1IMT; NMR; -; A=1-80.
DR   AlphaFoldDB; P25687; -.
DR   SMR; P25687; -.
DR   EvolutionaryTrace; P25687; -.
DR   GO; GO:0005576; C:extracellular region; EXP:UniProtKB.
DR   GO; GO:0001935; P:endothelial cell proliferation; IEA:TreeGrafter.
DR   Gene3D; 2.10.80.10; Lipase, subunit A; 1.
DR   InterPro; IPR009523; Prokineticin.
DR   InterPro; IPR023569; Prokineticin_domain.
DR   PANTHER; PTHR18821:SF2; DICKKOPF-RELATED PROTEIN 3-LIKE; 1.
DR   PANTHER; PTHR18821; PROKINETICIN; 1.
DR   Pfam; PF06607; Prokineticin; 1.
DR   SUPFAM; SSF57190; Colipase-like; 2.
DR   PDBsum; 1IMT; -.
PE   1: Evidence at protein level;
KW   3D-structure; Direct protein sequencing; Disulfide bond;
KW   G protein-coupled receptor impairing toxin; Secreted; Toxin.
FT   CHAIN           1..81
FT                   /note="Toxin MIT1"
FT                   /evidence="ECO:0000303|PubMed:10567694"
FT                   /id="PRO_0000165469"
FT   DISULFID        7..19
FT                   /evidence="ECO:0000269|PubMed:9761684"
FT   DISULFID        13..31
FT                   /evidence="ECO:0000269|PubMed:9761684"
FT   DISULFID        18..59
FT                   /evidence="ECO:0000269|PubMed:9761684"
FT   DISULFID        41..67
FT                   /evidence="ECO:0000269|PubMed:9761684"
FT   DISULFID        61..77
FT                   /evidence="ECO:0000269|PubMed:9761684"
FT   VARIANT         72
FT                   /note="P -> Q (in protein A')"
FT   HELIX           10..12
FT                   /evidence="ECO:0007829|PDB:1IMT"
FT   STRAND          17..21
FT                   /evidence="ECO:0007829|PDB:1IMT"
FT   STRAND          29..33
FT                   /evidence="ECO:0007829|PDB:1IMT"
FT   STRAND          66..71
FT                   /evidence="ECO:0007829|PDB:1IMT"
FT   STRAND          74..78
FT                   /evidence="ECO:0007829|PDB:1IMT"
SQ   SEQUENCE   81 AA;  8604 MW;  5F6B703434338B03 CRC64;
     AVITGACERD LQCGKGTCCA VSLWIKSVRV CTPVGTSGED CHPASHKIPF SGQRMHHTCP
     CAPNLACVQT SPKKFKCLSK S
//