title: Isolation and characterization of the tobramycin biosynthetic gene cluster from Streptomyces tenebrarius.
abstract: The biosynthetic gene cluster for tobramycin, a 2-deoxystreptamine-containing aminoglycoside antibiotic, was isolated from Streptomyces tenebrarius ATCC 17920. A genomic library of S. tenebrarius was constructed, and a cosmid, pST51, was isolated by the probes based on the core regions of 2-deoxy-scyllo-inosose (DOI) synthase, and L-glutamine:DOI aminotransferase and L-glutamine:scyllo-inosose aminotransferase. Sequencing of 33.9 kb revealed 24 open reading frames (ORFs) including putative tobramycin biosynthetic genes. We demonstrated that one of these ORFs, tbmA, encodes DOI synthase by in vitro enzyme assay of the purified protein. The catalytic residues of TbmA and dehydroquinate synthase were studied by homology modeling. The gene cluster found is likely to be involved in the biosynthesis of tobramycin.
authors.affiliation: Institute of Biomolecule Reconstruction, Sun Moon University, #100, Kalsan-ri, Tangjeong-myeon, Asansi, Chungnam 336-708, South Korea.
authors.forename: Madan Kumar
authors.initials: MK
authors.lastname: Kharel
authors.forename: Devi Bahadur
authors.initials: DB
authors.lastname: Basnet
authors.forename: Hei Chan
authors.initials: HC
authors.lastname: Lee
authors.forename: Kwangkyoung
authors.initials: K
authors.lastname: Liou
authors.forename: Jin Suk
authors.initials: JS
authors.lastname: Woo
authors.forename: Byung-Gee
authors.initials: BG
authors.lastname: Kim
authors.forename: Jae Kyung
authors.initials: JK
authors.lastname: Sohng
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D002076:Butirosin Sulfate / Q000096:biosynthesis; D007294:Inositol / Q000031:analogs & derivatives* / Q000378:metabolism; D008190:Lyases / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D005810:Multigene Family; D016366:Open Reading Frames; D017422:Sequence Analysis, DNA; D013302:Streptomyces / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D014031:Tobramycin / Q000096:biosynthesis*
chemical_list: D001426:Bacterial Proteins; D007294:Inositol; D002076:Butirosin Sulfate; C075548:2-deoxyinosose; D008190:Lyases; C085631:2-deoxy-scyllo-inosose synthase; D014031:Tobramycin