title: Structural and Functional Basis of C-Methylation of Coumarin Scaffolds by NovO.
abstract: C-methylation of aromatic small molecules by C-methyltransferases (C-MTs) is an important biological transformation that involves C-C bond formation using S-adenosyl-l-methionine (SAM) as the methyl donor. Here, two advances in the mechanistic understanding of C-methylation of the 8-position of coumarin substrates catalyzed by the C-MT NovO from Streptomyces spheroides are described. First, a crystal structure of NovO reveals the Arg116-Asn117 and His120-Arg121 motifs are essential for coumarin substrate binding. Second, the active-site His120 is responsible for deprotonation of the phenolic 7-hydroxyl group on the coumarin substrate, activating the rate-determining methyl transfer step from SAM. This work expands our mechanistic knowledge of C-MTs, which could be used in the downstream development of engineered biocatalysts for small molecule C-alkylations.
authors.affiliation: GlaxoSmithKline Medicines Research Centre , Gunnels Wood Road, Stevenage, SG1 2NY , United Kingdom.|WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde , 295 Cathedral Street, Glasgow G1 1XL, Scotland, United Kingdom.
authors.forename: Joanna C
authors.initials: JC
authors.lastname: Sadler
authors.affiliation: GlaxoSmithKline Medicines Research Centre , Gunnels Wood Road, Stevenage, SG1 2NY , United Kingdom.
authors.forename: Chun-Wa H
authors.initials: CH
authors.lastname: Chung
authors.affiliation: GlaxoSmithKline Medicines Research Centre , Gunnels Wood Road, Stevenage, SG1 2NY , United Kingdom.
authors.forename: Julie E
authors.initials: JE
authors.lastname: Mosley
authors.affiliation: WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde , 295 Cathedral Street, Glasgow G1 1XL, Scotland, United Kingdom.
authors.forename: Glenn A
authors.identifier: 0000-0002-4896-113X
authors.initials: GA
authors.lastname: Burley
authors.affiliation: GlaxoSmithKline Medicines Research Centre , Gunnels Wood Road, Stevenage, SG1 2NY , United Kingdom.
authors.forename: Luke D
authors.initials: LD
authors.lastname: Humphreys
mesh_terms: D002384:Catalysis; D003374:Coumarins / Q000378:metabolism*; D018360:Crystallography, X-Ray; D008745:Methylation; D008780:Methyltransferases / Q000378:metabolism; D015394:Molecular Structure; D009675:Novobiocin / Q000096:biosynthesis / Q000737:chemistry; D013302:Streptomyces / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D003374:Coumarins; D009675:Novobiocin; C030123:coumarin; D008780:Methyltransferases