title: Characterization of L-glutamine:2-deoxy-scyllo-inosose aminotransferase (tbmB) from Streptomyces tenebrarius.
abstract: 2-Deoxystreptamine (DOS)-containing aminoglycoside-aminocyclitol (AmAc) antibiotics represent the majority of clinically important AmAcs. Biosynthetic investigations of formation of DOS in actinomycetes are limited to the characterization of 2-deoxy-scyllo-inosose synthase, the first step enzyme of the DOS biosynthetic pathway. A gene encoding L-glutamine:2-deoxy-scyllo-inosose aminotransferase (tbmB) from the tobramycin producer Streptomyces tenebrarius was expressed heterologously in Escherichia coli. The conversions of 2-deoxy-scyllo-inosose to 2-deoxy-scyllo-inosamine and scyllo-inosose to scyllo-inosamine with the activity of TbmB were determined in vitro. The results indicate that tbmB catalyzes the second step of the DOS biosynthetic pathway during the biosynthesis of 2-deoxystreptamine, a subunit of tobramycin, in S. tenebrarius.
authors.affiliation: Institute of Biomolecule Reconstruction, Sun Moon University, 100 Kalsanri, Tangjeonmyun, Asansi, Chungnam 336-708, Korea.
authors.forename: Madan K
authors.initials: MK
authors.lastname: Kharel
authors.forename: Bimala
authors.initials: B
authors.lastname: Subba
authors.forename: Hei Chan
authors.initials: HC
authors.lastname: Lee
authors.forename: Kwangkyoung
authors.initials: K
authors.lastname: Liou
authors.forename: Jae Kyung
authors.initials: JK
authors.lastname: Sohng
mesh_terms: D021241:Spectrometry, Mass, Electrospray Ionization; D013302:Streptomyces / Q000201:enzymology*; D000637:Transaminases / Q000737:chemistry / Q000378:metabolism*
chemical_list: C471253:L-glutamine 2-deoxy-scyllo-inosose aminotransferase; D000637:Transaminases