Function
FAD-linked oxidoreductase; part of the gene cluster that mediates the biosynthesis of communesins, a prominent class of indole alkaloids with great potential as pharmaceuticals (PubMed:25571861). Communesins are biosynthesized by the coupling of tryptamine and aurantioclavine, two building blocks derived from L-tryptophan (PubMed:25571861). The L-tryptophan decarboxylase cnsB converts L-tryptophan to tryptamine, whereas the tryptophan dimethylallyltransferase cnsF converts L-tryptophan to 4-dimethylallyl tryptophan which is further transformed to aurantioclavine by the aurantioclavine synthase cnsA, probably aided by the catalase cnsD (PubMed:25571861). The cytochrome P450 monooxygenase cnsC catalyzes the heterodimeric coupling between the two different indole moieties, tryptamine and aurantioclavine, to construct vicinal quaternary stereocenters and yield the heptacyclic communesin scaffold (PubMed:26963294). The O-methyltransferase cnsE then methylates the communesin scaffold to produce communesin K, the simplest characterized communesin that contains the heptacyclic core (PubMed:25571861). The dioxygenase cnsJ converts communesin K into commmunesin I (PubMed:25571861). Acylation to introduce the hexadienyl group at position N16 of communesin I by the acyltransferase cnsK leads to the production of communesin B. The hexadienyl group is produced by the highly reducing polyketide synthase cnsI, before being hydrolytically removed from cnsI by the serine hydrolase cnsH, converted into hexadienyl-CoA by the CoA ligase cnsG, and then transferred to commmunesin I by cnsK (PubMed:25571861). Surprisingly, cnsK may also be a promiscuous acyltransferase that can tolerate a range of acyl groups, including acetyl-, propionyl-, and butyryl-CoA, which lead to communesins A, G and H respectively (PubMed:25571861). The roles of the alpha-ketoglutarate-dependent dioxygenases cnsM and cnsP have still to be determined (PubMed:25571861).
Sequence
MEGCTTRDSTGLGLGERFNQRGNVFLRLVSHVQCAIKFAKNHNLRLVIRNTGHDGSGRSSAPGSFEIHTHHLKHTHYHDDFQPVGAVTTSGPAVTVGAGVILGDLYAEGARQGYTVVGGVCPTVGFVGGFLQGGGVSGKFSHNRGLAVDNVLEIQAVTADGDLVVANDYHNQDLFWALRGGGGGTFAVVTQATVRVFPDVPCVTTQLAVSAPEGLDDHSWMQVLELLLRGLRSFNEERIAGEFHLRPDPLSAILTLHFLNTSDLDSVDRRLAALIDKFRTSEIPHIYSSKSHALEVPRSVEAKLYASHELTSVQMPVLYSLDPSYKVSYLNMGDPNDADFRNVYWGPNYERLLALKQKWDVDALFITRLGKRHDVMNTIPSTGAGADMRSFNRDIYDLLRNHAEDPRLNEVWTAINTVTEWVDWITSNGARMIPSDIAFRFWMLRVYMTHDWGCGLTSSTAEL