Fig. 1

Glutarate hydroxylase and l-2-hydroxyglutarate oxidase are induced during glutarate utilization of P. putida KT2440. CsiD, glutarate hydroxylase; l-2-hydroxyglutarate, l-2-HG; LhgO, l-2-hydroxyglutarate oxidase. a The pathways of glutarate metabolism in P. putida KT2440. Besides the well-studied glutaryl-CoA dehydrogenation pathway requiring GDH, a catabolic pathway involved with l-2-HG anabolism and catabolism is proposed (in red). b Growth of P. putida KT2440 and its gdh mutant on glutarate. Growth (closed symbols) and the consumption of glutarate (open symbols) of wild-type P. putida KT2440 (squares) and its gdh mutant (triangles) was measured in MSM supplemented with 5 g L⁻¹ glutarate as the sole carbon source. Data shown are mean ± s.d. (n = 3 independent experiments). c Schematic representation of the gene clusters of E. coli K-12 and P. putida KT2440 containing csiD and lhgO. Orthologs are shown with matching colors and the identities of protein sequences are shown below the corresponding genes of P. putida KT2440. Arrows indicate the direction of gene transcription. The location of davT and davD in the genome of P. putida KT2440 and the roles of DavT and DavD involved in the glutarate production from 5-aminovalerate are also shown. d Agarose gel electrophoresis of csiD and lhgO RT-PCR products. RT-PCRs from mRNAs of P. putida KT2440 cells grown in 5 g L⁻¹ glutarate (lanes 2 and 4) or 5 g L⁻¹ pyruvate (lanes 3 and 5) as sole carbon sources were performed. The reactions were conducted in the presence of a reverse transcriptase (lanes 4 and 5) or in the absence of the enzyme (lanes 2 and 3, as a negative control). Genomic DNA was used as a positive control (lane 1). Lane M, molecular size marker. Numbers on the left present the sizes of the markers (in base pairs)