FlhD/FlhC is a regulator of anaerobic respiration and the Entner-Doudoroff pathway through induction of the methyl-accepting chemotaxis protein Aer.
The 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. An flhD::Kan insertion and an aer deletion were independently introduced into two Escherichia coli K-12 strains, and the effects upon gene regulation were investigated. Altogether, the flhD::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 increased gltBD, gcvTHP, and ompT expression. The regulation of half of these genes was subsequently confirmed with reporter gene fusions, enzyme assays, and real-time PCR. Growth phenotypes of flhD and flhC mutants were determined with Phenotype MicroArrays and correlated with gene expression.
Prüss
Birgit M
BM
Department of Microbiology and Immunology, University of Illinois at Chicago, 60612-7344, USA. pruess@UIC.EDU
Campbell
John W
JW
Van Dyk
Tina K
TK
Zhu
Charles
C
Kogan
Yakov
Y
Matsumura
Philip
P
D000693:Anaerobiosis; D001426:Bacterial Proteins; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002633:Chemotaxis; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D036341:Intercellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D000072236:Methyl-Accepting Chemotaxis Proteins; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation / Q000379:methods; D009876:Operon; D010101:Oxygen Consumption; D010427:Pentose Phosphate Pathway; D010734:Phosphogluconate Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*
C108679:Aer protein, E coli; D001426:Bacterial Proteins; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D036341:Intercellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; D015534:Trans-Activators; C090552:flhC protein, E coli; C090553:flhD protein, E coli; D010734:Phosphogluconate Dehydrogenase