Characterization of recombinant biosynthetic precursors of the cysteine tryptophylquinone cofactors of l-lysine-epsilon-oxidase and glycine oxidase from Marinomonas mediterranea

摘要: The lysine-e-oxidase, LodA, and glycine oxidase, GoxA, from Marinomonas mediteranea each possesses a cysteine tryptophylquinone (CTQ) cofactor. This cofactor is derived posttranslational modifications which are covalent crosslinking of tryptophan residues incorporation two oxygen atoms into the indole ring Trp. In this manuscript, it shown that recombinant synthesis LodA GoxA containing fully synthesized CTQ requires coexpression partner flavoprotein, LodB for GoxB not interchangeable. An inactive precursor or contained monohydroxylated Trp residue no crosslink to Cys was isolated soluble fraction when they were expressed alone. structure revealed an Asp close conserved in quinohemoprotein amine dehydrogenase (QHNDH), CTQ, methylamine (MADH) (TTQ) as To study role precursor, Asp-512 mutated Ala. When mutant protein coexpressed with at all, suggesting initial LodB-independent hydroxylation A similar had been proposed MADH. It noteworthy formation TTQ MADH also accessory enzyme its biosynthesis but diheme MauG flavoprotein. results presented reveal novel mechanisms post-translational modification involved generation protein-derived cofactors. article part Special Issue entitled: Cofactor-dependent proteins: evolution, chemical diversity bio-applications.