抄録
The metabolic network consists of enzymes and chemical compounds. However, a large number of metabolic pathways remain unknown, and many enzymes are missing even in known metabolic pathways. We employed biochemical and bioinformatic approaches to identify several missing enzyme genes in lysine degradation pathways in Pseudomonas. First, we purified and characterized a novel NADPH-dependent enzyme, N-methyl-L-amino acid dehydrogenase from P. putida. Biochemical and genetic studies redefined its physiological role as Δ^1 -piperideine-2-carboxylate reductase, a missing enzyme in the D-lysine degradation pathway. Second, we predicted several missing enzyme genes to reconstruct the lysine degradation pathway of P. aeruginosa and confirmed PA0266 as 5-aminovalerate aminotransferase and PA0265 as glutarate semialdehyde dehydrogenase. Finally, we predicted a gene for L-lysine-2-monooxygenase by comparing its amino acid composition data with those of all ORFs in the P. putida genome. A gene for 5-aminovaleramidase was found to locate adjacent to the L-lysine-2-monooxygenase gene in the genome.
