Journal of Bacteriology · 2003 · 96 citations · 42 references
Life SciencesGeneticsMolecular BiologyGene ExpressionTranscriptionTranscriptional RegulationBacterial Gene RegulationEnzyme RegulationGene Regulation In MicrobesHeterologous Protein ExpressionOperon OrganizationTranscriptional Regulation In ProkaryotesAnaerobic Fermentation ConditionsEnzyme Activation MechanismsEscherichia ColiIsoenzyme SpecificityIsoenzyme-specific ActivationLac Operon OrganizationOperon Architecture
On the basis of hyf-lacZ fusion studies, the hyf operon of Escherichia coli, noted for encoding the fourth hydrogenase isoenzyme (HYD4), is not expressed at a significant level in a wild-type strain. However, mutant FhlA proteins (constitutive activators of the hyc-encoded hydrogenase 3 isoenzyme) activated hyf-lacZ. HyfR, an FhlA homolog encoded by the hyfR gene present at the end of the hyf operon, also activated transcription of hyf-lacZ but did so only when hyfR was expressed from a heterologous promoter. The HYD4 isoenzyme did not substitute for HYD3 in H(2) production. Optimum expression of hyf-lacZ required the presence of cyclic AMP receptor protein-cyclic AMP complex and anaerobic conditions when HyfR was the activator.
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The Complete Genome Sequence of <i>Escherichia coli</i> K-12
Frederick R. Blattner, Guy Plunkett, Craig A. Bloch et al. · Science · 1997 · 7.5K citations