title: Unique O-ribosylation in the biosynthesis of butirosin.
abstract: Using a comparative genetics approach, one or more of the BtrA, BtrL, BtrP, and BtrV proteins encoded in the butirosin biosynthetic gene cluster (btr) from Bacillus circulans SANK72073 were identified as being responsible for an O-ribosylation process leading to the formation of ribostamycin, a key intermediate in this, and related antibiotic biosynthetic pathways. Functional analysis of the recombinantly expressed proteins revealed that both BtrL and BtrP were responsible for the ribosylation of neamine, using 5-phosphoribosyl-1-diphosphate (PRPP) as the ribosyl donor. Further detailed analysis indicated that this process occurs via two discrete steps: with BtrL first catalyzing the phosphoribosylaion of neamine to form 5''-phosphoribostamycin, followed by a BtrP-catalyzed dephosphorylation to generate ribostamycin. To the best of our knowledge, this is the first time that the functional characterization of a glycosyltransferase from an aminoglycoside biosynthetic gene cluster has been reported.
authors.affiliation: Department of Chemistry, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8551, Japan.
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Kudo
authors.forename: Takuya
authors.initials: T
authors.lastname: Fujii
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Kinoshita
authors.forename: Tadashi
authors.initials: T
authors.lastname: Eguchi
mesh_terms: D000617:Aminoglycosides / Q000096:biosynthesis; D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D001407:Bacillus / Q000378:metabolism; D002076:Butirosin Sulfate / Q000096:biosynthesis*; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000378:metabolism; D008969:Molecular Sequence Data; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D012266:Ribose / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D002076:Butirosin Sulfate; D012266:Ribose; D010744:Phosphoric Monoester Hydrolases