title: Molecular characterization of lysR-lysXE, gcdR-gcdHG and amaR-amaAB operons for lysine export and catabolism: a comprehensive lysine catabolic network in Pseudomonas aeruginosa PAO1.
abstract: Among multiple interconnected pathways for l-Lysine catabolism in pseudomonads, it has been reported that Pseudomonas aeruginosa PAO1 employs the decarboxylase and the transaminase pathways. However, up until now, knowledge of several genes involved in operation and regulation of these pathways was still missing. Transcriptome analyses coupled with promoter activity measurements and growth phenotype analyses led us to identify new members in l-Lys and d-Lys catabolism and regulation, including gcdR-gcdHG for glutarate utilization, dpkA, amaR-amaAB and PA2035 for d-Lys catabolism, lysR-lysXE for putative l-Lys efflux and lysP for putative l-Lys uptake. The gcdHG operon encodes an acyl-CoA transferase (gcdG) and glutaryl-CoA dehydrogenase (gcdH) and is under the control of the transcriptional activator GcdR. Growth on l-Lys was enhanced in the mutants of lysX and lysE, supporting the operation of l-Lys efflux. The transcriptional activator LysR is responsible for l-Lys specific induction of lysXE and the PA4181-82 operon of unknown function. The putative operator sites of GcdR and LysR were deduced from serial deletions and comparative genomic sequence analyses, and the formation of nucleoprotein complexes was demonstrated with purified His-tagged GcdR and LysR. The amaAB operon encodes two enzymes to convert pipecolate to 2-aminoadipate. Induction of the amaAB operon by l-Lys, d-Lys and pipecolate requires a functional AmaR, supporting convergence of Lys catabolic pathways to pipecolate. Growth on pipecolate was retarded in the gcdG and gcdH mutants, suggesting the importance of glutarate in pipecolate and 2-aminoadipate utilization. Furthermore, this study indicated links in the control of interconnected networks of lysine and arginine catabolism in P. aeruginosa.
authors.affiliation: Department of Biology, Georgia State University, Atlanta, GA 30303, USA.
authors.forename: Sai
authors.initials: S
authors.lastname: Madhuri Indurthi
authors.affiliation: Department of Biology, Georgia State University, Atlanta, GA 30303, USA.
authors.forename: Han-Ting
authors.initials: HT
authors.lastname: Chou
authors.affiliation: Department of Biology, Georgia State University, Atlanta, GA 30303, USA.|Department of Clinical Laboratory and Nutritional Sciences, UMass Lowell, Lowell, MA 01854, USA.
authors.forename: Chung-Dar
authors.initials: CD
authors.lastname: Lu
mesh_terms: D015074:2-Aminoadipic Acid / Q000737:chemistry; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D001692:Biological Transport / Q000235:genetics; D002262:Carboxy-Lyases / Q000235:genetics* / Q000378:metabolism; D015256:Coenzyme A-Transferases / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D016680:Genome, Bacterial / Q000235:genetics; D005977:Glutarates / Q000378:metabolism; D050770:Glutaryl-CoA Dehydrogenase / Q000235:genetics*; D008239:Lysine / Q000378:metabolism*; D010875:Pipecolic Acids / Q000737:chemistry; D011401:Promoter Regions, Genetic / Q000235:genetics; D011550:Pseudomonas aeruginosa / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion / Q000235:genetics; D000637:Transaminases / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics*; D015533:Transcriptional Activation / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D005977:Glutarates; D010875:Pipecolic Acids; D014157:Transcription Factors; D015074:2-Aminoadipic Acid; C073470:LysR protein, Bacteria; D050770:Glutaryl-CoA Dehydrogenase; D000637:Transaminases; D015256:Coenzyme A-Transferases; C031212:acyl-CoA transferase; D002262:Carboxy-Lyases; C031345:pipecolic acid; D008239:Lysine