A gene cluster for biosynthesis of kanamycin from Streptomyces kanamyceticus: comparison with gentamicin biosynthetic gene cluster.
Gene clusters for the biosynthesis of kanamycin (Km) and gentamicin (Gm) were isolated from the genomic libraries of Streptomyces kanamyceticus and Micromonospora echinospora, respectively. The sequencing of the 47 kb-region of S. kanamyceticus genomic DNA revealed 40 putative open reading frames (ORFs) encoding Km biosynthetic proteins, regulatory proteins, and resistance and transport proteins. Similarly, the sequencing of 32.6 kb genomic DNA of M. echinospora revealed a Gm biosynthetic gene cluster flanked by resistant genes. Biosynthetic pathways for the formation of Km were proposed by the comparative study of biosynthetic genes. Out of 12 putative Km biosynthetic genes, kanA was expressed in Escherichia coli and determined its function as a 2-deoxy-scyllo-inosose synthase. Furthermore, the acetylations of aminoglycoside-aminocyclitols (AmAcs) by Km acetyltransferase (KanM) were also demonstrated. The acetylated derivatives completely lost their antibacterial activities against Bacillus subtilis. The comparative genetic studies of Gm, Km, tobramycin (Tm), and butirosin (Bn) reveal their similar biosynthetic routes and provide a framework for the further biosynthetic studies.
Kharel
Madan K
MK
Institute of Biomolecule Reconstruction, SunMoon University, Asan, Chung-nam, 336-708, South Korea.
Subba
Bimala
B
Basnet
Devi B
DB
Woo
Jin Suk
JS
Lee
Hei Chan
HC
Liou
Kwangkyoung
K
Sohng
Jae Kyung
JK
D001483:Base Sequence; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D003360:Cosmids; D017931:DNA Primers; D004591:Electrophoresis, Polyacrylamide Gel; D005839:Gentamicins / Q000096:biosynthesis*; D007612:Kanamycin / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D005810:Multigene Family; D013302:Streptomyces / Q000235:genetics* / Q000378:metabolism
D017931:DNA Primers; D005839:Gentamicins; D007612:Kanamycin