FlhD/FlhC Is a Regulator of Anaerobic Respiration and the Entner-Doudoroff Pathway through Induction of the Methyl-Accepting Chemotaxis Protein Aer

• DOI: 10.1128/jb.185.2.534-543.2003
• Publication Date: 2003-01-02T19:30:24Z
• Authors: Birgit M. Prüβ; John W. Campbell; Tina K. Van Dyk; Charles Zhu; Yakov Kogan; Philip Matsumura
• Keywords: 0301 basic medicine; Chemotaxis; Escherichia coli Proteins; Phosphogluconate Dehydrogenase; Membrane Proteins; Methyl-Accepting Chemotaxis Proteins; Gene Expression Regulation, Bacterial; DNA-Binding Proteins; Pentose Phosphate Pathway; 03 medical and health sciences; Oxygen Consumption; Bacterial Proteins; Operon; Escherichia coli; Trans-Activators; Intercellular Signaling Peptides and Proteins; Anaerobiosis; Carrier Proteins; Oligonucleotide Array Sequence Analysis

ABSTRACTThe regulation by two transcriptional activators of flagellar expression (FlhD and FlhC) and the chemotaxis methyl-accepting protein Aer was studied with glass slide DNA microarrays. AnflhD::Kan insertion and anaerdeletion were independently introduced into twoEscherichia coliK-12 strains, and the effects upon gene regulation were investigated. Altogether, theflhD::Kan insertion altered the expression of 29 operons of known function. Among them was Aer, which in turn regulated a subset of these operons, namely, the ones involved in anaerobic respiration and the Entner-Doudoroff pathway. In addition, FlhD/FlhC repressed enzymes involved in aerobic respiration and regulated many other metabolic enzymes and transporters in an Aer-independent manner. Expression of 12 genes of uncharacterized function was also affected. FlhD increasedgltBD,gcvTHP, andompTexpression. The regulation of half of these genes was subsequently confirmed with reporter gene fusions, enzyme assays, and real-time PCR. Growth phenotypes offlhDandflhCmutants were determined with Phenotype MicroArrays and correlated with gene expression.