title: Genetic analysis of the assimilation of C5-dicarboxylic acids in Pseudomonas aeruginosa PAO1.
abstract: There is a wealth of information on the genetic regulation and biochemical properties of bacterial C4-dicarboxylate transport systems. In sharp contrast, there are far fewer studies describing the transport and assimilation of C5-dicarboxylates among bacteria. In an effort to better our understanding on this subject, we identified the structural and regulatory genes necessary for the utilization of α-ketoglutarate (α-KG) in Pseudomonas aeruginosa PAO1. The PA5530 gene, encoding a putative dicarboxylate transporter, was found to be essential for the growth of P. aeruginosa PAO1 on both α-KG and glutarate (another C5-dicarboxylate). Metabolite analysis confirmed that the PA5530 gene was necessary for the uptake of extracellular α-KG. Like other substrate-inducible transporter genes, expression of the PA5530 gene was induced by extracellular C5-dicarboxylates. It was later found that the expression of the PA5530 gene was driven solely by a -24/-12 promoter recognized by the alternative sigma factor RpoN. Surprisingly, the enhancer binding protein MifR, which is known to have an essential role in biofilm development, was required for the expression of the PA5530 gene. The MifR protein is homologous to other transcriptional regulators involved in dicarboxylate assimilation, suggesting that MifR might interact with RpoN to activate the expression of the PA5530 gene in response to extracellular C5-dicarboxylates, especially α-KG. The results of this study provide a framework for exploring the assimilation of α-KG in other pseudomonads.
authors.affiliation: Department of Chemistry, State University of New York, College of Environmental Science and Forestry, Syracuse, New York, USA.
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Lundgren
authors.affiliation: Department of Chemistry, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Luis Roberto
authors.initials: LR
authors.lastname: Villegas-Peñaranda
authors.affiliation: Department of Chemistry, State University of New York, College of Environmental Science and Forestry, Syracuse, New York, USA.
authors.forename: Joshua R
authors.initials: JR
authors.lastname: Harris
authors.affiliation: Department of Chemistry, State University of New York, College of Environmental Science and Forestry, Syracuse, New York, USA.
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Mottern
authors.affiliation: Department of Chemistry, State University of New York, College of Environmental Science and Forestry, Syracuse, New York, USA.
authors.forename: Diana M
authors.initials: DM
authors.lastname: Dunn
authors.affiliation: Department of Chemistry, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Christopher N
authors.initials: CN
authors.lastname: Boddy
authors.affiliation: Department of Chemistry, State University of New York, College of Environmental Science and Forestry, Syracuse, New York, USA Center for Applied Microbiology, State University of New York College of Environmental Science and Forestry, Syracuse, New York, USA ctnomura@esf.edu.
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Nomura
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001692:Biological Transport; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D007656:Ketoglutaric Acids / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000235:genetics* / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D007656:Ketoglutaric Acids