Muscarinic toxin 7

Muscarinic toxin 7 (MT7) is one member of a family of small peptides of 65 amino acid residues derived from the venom of African mamba snakes (Dendroaspis angusticeps), which mainly target M1-subtype of muscarinic receptor. Muscarinic toxins like the nicotinic toxins have the three-finger fold structure, characteristic of the large superfamily of toxins that act at cholinergic synapses.

Muscarinic toxin 7
Crystal structure of Muscarinic toxin 7 (MT7) from PDB 2VLW [1]
Identifiers
Symbol	MT7
SCOP	1F94
SUPERFAMILY	1F94

MT7 is likely to bind to the human M1 receptor in its dimer form with the tips of MT7 loops II and III contacting one hM1 protomer and the tip of loop I binds to the other protomer.^[2]

References

1. Fruchart-Gaillard C, Mourier G, Marquer C, Stura E, Birdsall NJ, Servent D (December 2008). "Different interactions between MT7 toxin and the human muscarinic M1 receptor in its free and N-methylscopolamine-occupied states.". Mol Pharmacol. 74 (6): 1554–63. doi:10.1124/mol.108.050773. PMID 18784346.
2. Fruchart-Marquer C, Fruchart-Gaillard C, Letellier G, Marcon E, Mourier G, Zinn-Justin S, Ménez A, Servent D, Gilquin B (September 2011). "Structural model of ligand-G protein-coupled receptor (GPCR) complex based on experimental double mutant cycle data: MT7 snake toxin bound to dimeric hM1 muscarinic receptor.". J Biol Chem. 286 (36): 31661–75. doi:10.1074/jbc.M111.261404. PMC 3173127. PMID 21685390.