6533b7d7fe1ef96bd1268648
RESEARCH PRODUCT
Functioning of DcuC as the C 4 -Dicarboxylate Carrier during Glucose Fermentation by Escherichia coli
E. ZientzIngo G. JanauschGottfried UndenStephan Sixsubject
Physiology and MetabolismMolecular Sequence DataMutantStimulationBiologymedicine.disease_causeMicrobiologyBacterial ProteinsFumaratesConsensus SequenceEscherichia colimedicineTranscriptional regulationDicarboxylic AcidsAnaerobiosisPromoter Regions GeneticMolecular BiologyEscherichia coliPsychological repressionDicarboxylic Acid TransportersBinding SitesBase SequenceEscherichia coli ProteinsSuccinatesGene Expression Regulation BacterialKineticsResponse regulatorGlucoseBiochemistryFermentationFermentationEffluxCarrier ProteinsRibosomesdescription
ABSTRACT The dcuC gene of Escherichia coli encodes an alternative C 4 -dicarboxylate carrier (DcuC) with low transport activity. The expression of dcuC was investigated. dcuC was expressed only under anaerobic conditions; nitrate and fumarate caused slight repression and stimulation of expression, respectively. Anaerobic induction depended mainly on the transcriptional regulator FNR. Fumarate stimulation was independent of the fumarate response regulator DcuR. The expression of dcuC was not significantly inhibited by glucose, assigning a role to DcuC during glucose fermentation. The inactivation of dcuC increased fumarate-succinate exchange and fumarate uptake by DcuA and DcuB, suggesting a preferential function of DcuC in succinate efflux during glucose fermentation. Upon overexpression in a dcuC promoter mutant ( dcuC *), DcuC was able to compensate for DcuA and DcuB in fumarate-succinate exchange and fumarate uptake.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1999-06-15 | Journal of Bacteriology |