title: Nitrogen incorporation in the biosynthetic pathway of the nitrogen-containing polyketide, pamamycin in Streptomyces alboniger.
abstract: The biosynthetic pathway of pamamycin (1), a nitrogen-containing polyketide, was investigated using blocked mutants of Streptomyces alboniger. Hydroxy acids K (3), L (4) and S (5) were found in cultured materials of blocked mutants and the wild type strain, but no PM-ketone (2) was detected. Hydroxy acids 3, 4, 5 and de-N-methylhydroxy acid L (7) were converted into 1, but 2 nor de-N-methylpamamycin (6) were not. We also confirmed that 3 and 7 were converted into 4. These results showed that an amino group was introduced into the carbonyl group of 3 by transamination, and subsequent N-methylation led to 4 in the pamamycin biosynthetic pathway. Quantitative analyses of hydroxy acid intermediates 3, 4, and 5, and pamamycin (1) suggested that transamination was the rate-determining step in pamamycin biosynthesis.
authors.affiliation: Department of Plant Protection, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Saiwai-cho, Fuchu, Tokyo, Japan. natsume@cc.tuat.ac.jp
authors.forename: Makoto
authors.initials: M
authors.lastname: Hashimoto
authors.forename: Ikuko
authors.initials: I
authors.lastname: Kozone
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawaide
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Abe
authors.forename: Masahiro
authors.initials: M
authors.lastname: Natsume
mesh_terms: D005663:Furans / Q000737:chemistry / Q000378:metabolism; D006880:Hydroxy Acids / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D015394:Molecular Structure; D009154:Mutation; D009584:Nitrogen / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization; D013302:Streptomyces / Q000235:genetics / Q000378:metabolism*
chemical_list: D005663:Furans; D006880:Hydroxy Acids; C057558:panamycin 607; D009584:Nitrogen