title: Gene cluster in Micromonospora echinospora ATCC15835 for the biosynthesis of the gentamicin C complex.
abstract: Gentamicin is a 4,6-disubstituted aminocyclitol antibiotic complex synthesised by some members of the actinomycete genus Micromonospora. In a search for the gentamicin biosynthetic gene cluster we identified, using a cosmid library approach, a region of the M. echinospora ATCC15835 chromosome that encodes homologues of aminoglycoside biosynthesis genes including gntB-a close homologue of the 2-deoxy-scyllo-inosose synthase gene (btrC) from butirosin-producing Bacillus circulans. Insertional inactivation was achieved by homologous recombination with an internal gntB fragment-containing suicide plasmid, delivered by conjugal transfer from Escherichia coli. gntB disruptants were gentamicin nonproducing mutants as assayed by an ELISA antibiotic detection system, proving the association of gntB (or a downstream region) with gentamicin biosynthesis. The function of some open reading frames within the cluster, predicted by nucleotide database homology searching, is discussed with regards to their potential roles in gentamicin biosynthesis. The discovery of this genetic region represents the first report of a gene cluster involved in the biosynthesis of a 4,6-disubstituted aminocyclitol antibiotic.
authors.affiliation: Biological Sciences Department, Gibbett Hill Campus, University of Warwick, Coventry, UK.
authors.forename: Jamie
authors.initials: J
authors.lastname: Unwin
authors.forename: Scott
authors.initials: S
authors.lastname: Standage
authors.forename: Dylan
authors.initials: D
authors.lastname: Alexander
authors.forename: Thomas
authors.initials: T
authors.lastname: Hosted
authors.forename: Ann C
authors.initials: AC
authors.lastname: Horan
authors.forename: Elizabeth M H
authors.initials: EM
authors.lastname: Wellington
mesh_terms: D005839:Gentamicins / Q000096:biosynthesis*; D008847:Micromonospora / Q000235:genetics*; D005810:Multigene Family; D016366:Open Reading Frames
chemical_list: D005839:Gentamicins; C100093:gentamicin C