title: The biosynthetic pathway of the aminonucleoside antibiotic puromycin, as deduced from the molecular analysis of the pur cluster of Streptomyces alboniger.
abstract: The pur cluster which encodes the puromycin biosynthetic pathway from Streptomyces alboniger was subcloned as a 13-kilobase fragment in plasmid pIJ702 and expressed in an apparently regulated manner in the heterologous host Streptomyces lividans. The sequencing of a 9.1-kilobase DNA fragment completed the sequence of pur. This permitted identification of seven new open reading frames in the order: napH, pur7, pur10, pur6, pur4, pur5, and pur3. The latter is followed by the known pac, dmpM, and pur8 genes. Nine open reading frames are transcribed rightward as a unit in opposite direction to that of the pur8 gene which is expressed as a monocistronic transcript from the right-most end. napH encodes the known N-acetylpuromycin N-acetylhydrolase. The deduced products from other open reading frames present similarities to: NTP pyrophosphohydrolases (pur7), several oxidoreductases (pur10), the putative LmbC protein of the lincomycin biosynthetic pathway from Streptomyces lincolnensis (pur6), S-adenosylmethionine-dependent methyltransferases (pur5), a variety of presumed aminotransferases (pur4), and several monophosphatases (pur3). According to these similarities and to previous biochemical work, a puromycin biosynthetic pathway has been deduced. No cluster-associated regulatory gene was found. However, both pur10 and pur6 genes contain a TTA codon, which suggests that they are translationally controlled by the bldA gene product, a specific tRNA(Leu).
authors.affiliation: Centro de Biologia Molecular Severo Ochoa, Consejo Superior de Investigaciones Cientificas, Madrid, Spain.
authors.forename: J A
authors.initials: JA
authors.lastname: Tercero
authors.forename: J C
authors.initials: JC
authors.lastname: Espinosa
authors.forename: R A
authors.initials: RA
authors.lastname: Lacalle
authors.forename: A
authors.initials: A
authors.lastname: Jiménez
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D001483:Base Sequence; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D005810:Multigene Family; D016366:Open Reading Frames; D010957:Plasmids; D011691:Puromycin / Q000096:biosynthesis*; D012329:RNA, Bacterial / Q000096:biosynthesis; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid; D013302:Streptomyces / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D000900:Anti-Bacterial Agents; D012329:RNA, Bacterial; D011691:Puromycin