title: Genes encoding enzymes responsible for biosynthesis of L-lyxose and attachment of eurekanate during avilamycin biosynthesis.
abstract: The oligosaccharide antibiotic avilamycin A is composed of a polyketide-derived dichloroisoeverninic acid moiety attached to a heptasaccharide chain consisting of six hexoses and one unusual pentose moiety. We describe the generation of mutant strains of the avilamycin producer defective in different sugar biosynthetic genes. Inactivation of two genes (aviD and aviE2) resulted in the breakdown of the avilamycin biosynthesis. In contrast, avilamycin production was not influenced in an aviP mutant. Inactivation of aviGT4 resulted in a mutant that accumulated a novel avilamycin derivative lacking the terminal eurekanate residue. Finally, AviE2 was expressed in Escherichia coli and the gene product was characterized biochemically. AviE2 was shown to convert UDP-D-glucuronic acid to UDP-D-xylose, indicating that the pentose residue of avilamycin A is derived from D-glucose and not from D-ribose. Here we report a UDP-D-glucuronic acid decarboxylase in actinomycetes.
authors.affiliation: Institut für Pharmazeutische Wissenschaften, Pharmazeutische Biologie und Biotechnologie, Albert-Ludwigs-Universität Freiburg, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Hofmann
authors.forename: Raija
authors.initials: R
authors.lastname: Boll
authors.forename: Björn
authors.initials: B
authors.lastname: Heitmann
authors.forename: Gerd
authors.initials: G
authors.lastname: Hauser
authors.forename: Clemens
authors.initials: C
authors.lastname: Dürr
authors.forename: Anke
authors.initials: A
authors.lastname: Frerich
authors.forename: Gabriele
authors.initials: G
authors.lastname: Weitnauer
authors.forename: Steffen J
authors.initials: SJ
authors.lastname: Glaser
authors.forename: Andreas
authors.initials: A
authors.lastname: Bechthold
mesh_terms: D039903:Actinobacteria / Q000201:enzymology; D002240:Carbohydrate Sequence; D002262:Carboxy-Lyases / Q000096:biosynthesis* / Q000235:genetics*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D005947:Glucose / Q000378:metabolism; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009844:Oligosaccharides / Q000032:analysis / Q000096:biosynthesis* / Q000378:metabolism; D010429:Pentoses / Q000096:biosynthesis*
chemical_list: D009844:Oligosaccharides; D010429:Pentoses; C043333:lyxose; C006653:avilamycin; D002262:Carboxy-Lyases; C023257:UDPglucuronate decarboxylase; D005947:Glucose