title: Engineering biosynthetic pathways for deoxysugars: branched-chain sugar pathways and derivatives from the antitumor tetracenomycin.
abstract: Sugar biosynthesis cassette genes have been used to construct plasmids directing the biosynthesis of branched-chain deoxysugars: pFL942 (NDP-L-mycarose), pFL947 (NDP-4-deacetyl-L-chromose B), and pFL946/pFL954 (NDP-2,3,4-tridemethyl-L-nogalose). Expression of pFL942 and pFL947 in S. lividans 16F4, which harbors genes for elloramycinone biosynthesis and the flexible ElmGT glycosyltransferase of the elloramycin biosynthetic pathway, led to the formation of two compounds: 8-alpha-L-mycarosyl-elloramycinone and 8-demethyl-8-(4-deacetyl)-alpha-L-chromosyl-tetracenomycin C, respectively. Expression of pFL946 or pFL954 failed to produce detectable amounts of a novel glycosylated tetracenomycin derivative. Formation of these two compounds represents examples of the sugar cosubstrate flexibility of the ElmGT glycosyltransferase. The use of these cassette plasmids also provided insights into the substrate flexibility of deoxysugar biosynthesis enzymes as the C-methyltransferases EryBIII and MtmC, the epimerases OleL and EryBVII, and the 4-ketoreductases EryBIV and OleU.
authors.affiliation: Departamento de Biología Funcional and Instituto Universitario de Oncología, del Principado de Asturias (I.U.O.P.A), Universidad de Oviedo, 33006 Oviedo, Spain.
authors.forename: Felipe
authors.initials: F
authors.lastname: Lombó
authors.forename: Miranda
authors.initials: M
authors.lastname: Gibson
authors.forename: Lisa
authors.initials: L
authors.lastname: Greenwell
authors.forename: Alfredo F
authors.initials: AF
authors.lastname: Braña
authors.forename: Jürgen
authors.initials: J
authors.lastname: Rohr
authors.forename: José A
authors.initials: JA
authors.lastname: Salas
authors.forename: Carmen
authors.initials: C
authors.lastname: Méndez
mesh_terms: D000970:Antineoplastic Agents / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D002236:Carbohydrate Conformation; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D003837:Deoxy Sugars / Q000096:biosynthesis / Q000378:metabolism*; D015195:Drug Design; D015964:Gene Expression Regulation, Bacterial; D005818:Genetic Engineering / Q000379:methods*; D006801:Humans; D008968:Molecular Conformation; D009279:Naphthacenes / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D013302:Streptomyces / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
chemical_list: D000970:Antineoplastic Agents; D003837:Deoxy Sugars; D009279:Naphthacenes; C080889:5838 DNI