title: The metabolism of (R)-3-hydroxybutyrate is regulated by the enhancer-binding protein PA2005 and the alternative sigma factor RpoN in Pseudomonas aeruginosa PAO1.
abstract: A variety of soil-dwelling bacteria produce polyhydroxybutyrate (PHB), which serves as a source of energy and carbon under nutrient deprivation. Bacteria belonging to the genus Pseudomonas do not generally produce PHB but are capable of using the PHB degradation product (R)-3-hydroxybutyrate [(R)-3-HB] as a growth substrate. Essential to this utilization is the NAD+-dependent dehydrogenase BdhA that converts (R)-3-HB into acetoacetate, a molecule that readily enters central metabolism. Apart from the numerous studies that had focused on the biochemical characterization of BdhA, there was nothing known about the assimilation of (R)-3-HB in Pseudomonas, including the genetic regulation of bdhA expression. This study aimed to define the regulatory factors that govern or dictate the expression of the bdhA gene and (R)-3-HB assimilation in Pseudomonas aeruginosa PAO1. Importantly, expression of the bdhA gene was found to be specifically induced by (R)-3-HB in a manner dependent on the alternative sigma factor RpoN and the enhancer-binding protein PA2005.This mode of regulation was essential for the utilization of (R)-3-HB as a sole source of energy and carbon. However, non-induced levels of bdhA expression were sufficient for P. aeruginosa PAO1 to grow on ( ± )-1,3-butanediol, which is catabolized through an (R)-3-HB intermediate. Because this is, we believe, the first report of an enhancer-binding protein that responds to (R)-3-HB, PA2005 was named HbcR for (R)-3-hydroxybutyrate catabolism regulator.
authors: 1​Department of Chemistry, State University of New York - College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, New York, 13210, USA.
authors: Benjamin R
authors: BR
authors: Lundgren
authors: 1​Department of Chemistry, State University of New York - College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, New York, 13210, USA.
authors: Joshua R
authors: JR
authors: Harris
authors: 1​Department of Chemistry, State University of New York - College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, New York, 13210, USA.
authors: Zaara
authors: Z
authors: Sarwar
authors: 1​Department of Chemistry, State University of New York - College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, New York, 13210, USA.
authors: Ryan A
authors: RA
authors: Scheel
authors: 1​Department of Chemistry, State University of New York - College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, New York, 13210, USA 2​Center for Applied Microbiology, State University of New York - College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, New York, 13210, USA.
authors: Christopher T
authors: CT
authors: Nomura
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000378:metabolism*; D000090:Acetoacetates / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism*; D002072:Butylene Glycols / Q000378:metabolism; D002244:Carbon / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004734:Energy Metabolism; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D011550:Pseudomonas aeruginosa / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D051877:RNA Polymerase Sigma 54 / Q000378:metabolism*
chemical_list: D000090:Acetoacetates; D001426:Bacterial Proteins; D002072:Butylene Glycols; D004268:DNA-Binding Proteins; C028491:1,3-butylene glycol; C016635:acetoacetic acid; D002244:Carbon; D051877:RNA Polymerase Sigma 54; D020155:3-Hydroxybutyric Acid