title: Functional analysis of MycCI and MycG, cytochrome P450 enzymes involved in biosynthesis of mycinamicin macrolide antibiotics.
abstract: Macrolides are a class of valuable antibiotics that include a macrolactone ring, at least one appended sugar unit, and, in most cases, additional hydroxyl or epoxide groups installed by cytochrome P450 enzymes. These functional groups contribute to structural diversification and serve to improve the bioactivity profiles of natural products. Here, we have characterized in vitro two P450 enzymes from the mycinamicin biosynthetic pathway of Micromonospora griseorubida. First, MycCI was characterized as the C21 methyl hydroxylase of mycinamicin VIII, the earliest macrolide form in the postpolyketide synthase tailoring pathway. Moreover, we established that optimal activity of MycCI depends on the native ferredoxin MycCII. Second, MycG P450 catalyzes consecutive hydroxylation and epoxidation reactions with mycinamicin IV as initial substrate. These reactions require prior dimethylation of 6-deoxyallose to mycinose for effective conversion by the dual function MycG enzyme.
authors.affiliation: Faculty of Pharmaceutical Sciences, Toho University, Miyama, Funabashi, Chiba, Japan.
authors.forename: Yojiro
authors.initials: Y
authors.lastname: Anzai
authors.forename: Shengying
authors.initials: S
authors.lastname: Li
authors.forename: Mani Raj
authors.initials: MR
authors.lastname: Chaulagain
authors.forename: Kenji
authors.initials: K
authors.lastname: Kinoshita
authors.forename: Fumio
authors.initials: F
authors.lastname: Kato
authors.forename: John
authors.initials: J
authors.lastname: Montgomery
authors.forename: David H
authors.initials: DH
authors.lastname: Sherman
mesh_terms: D000900:Anti-Bacterial Agents / Q000096:biosynthesis* / Q000737:chemistry; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D007700:Kinetics; D018942:Macrolides / Q000737:chemistry / Q000378:metabolism*; D015394:Molecular Structure; D010802:Phylogeny; D017421:Sequence Analysis
chemical_list: D000900:Anti-Bacterial Agents; D018942:Macrolides; C026686:mycinamicins; D003577:Cytochrome P-450 Enzyme System