title: Direct linking of metabolism and gene expression in the proline utilization A protein from Escherichia coli.
abstract: The control of gene expression by enzymes provides a direct pathway for cells to respond to fluctuations in metabolites and nutrients. One example is the proline utilization A (PutA) protein from Escherichia coli. PutA is a membrane-associated enzyme that catalyzes the oxidation of L: -proline to glutamate using a flavin containing proline dehydrogenase domain and a NAD(+) dependent Delta(1)-pyrroline-5-carboxylate dehydrogenase domain. In some Gram-negative bacteria such as E. coli, PutA is also endowed with a ribbon-helix-helix DNA-binding domain and acts as a transcriptional repressor of the proline utilization genes. PutA switches between transcriptional repressor and enzymatic functions in response to proline availability. Molecular insights into the redox-based mechanism of PutA functional switching from recent studies are reviewed. In addition, new results from cell-based transcription assays are presented which correlate PutA membrane localization with put gene expression levels. General membrane localization of PutA, however, is not sufficient to activate the put genes.
authors.affiliation: Department of Biochemistry, University of Nebraska-Lincoln, N258 Beadle Center, 19th and Vine Street, Lincoln, NE 68588, USA.
authors.forename: Yuzhen
authors.initials: Y
authors.lastname: Zhou
authors.forename: Weidong
authors.initials: W
authors.lastname: Zhu
authors.forename: Padmanetra S
authors.initials: PS
authors.lastname: Bellur
authors.forename: Dustin
authors.initials: D
authors.lastname: Rewinkel
authors.forename: Donald F
authors.initials: DF
authors.lastname: Becker
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D004247:DNA / Q000737:chemistry; D004926:Escherichia coli / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D018698:Glutamic Acid / Q000737:chemistry; D007700:Kinetics; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D008954:Models, Biological; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D011392:Proline / Q000737:chemistry; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D020349:Surface Plasmon Resonance; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins; C080683:PutA protein, Bacteria; D018698:Glutamic Acid; D004247:DNA; D011392:Proline; D010100:Oxygen