Activation of the lac operon of Escherichia coli by a mutant FNR protein.
The FNR protein of E. coli is a transcriptional activator required for the expression of genes involved in anaerobic respiratory pathways. Site-directed mutagenesis was used to alter three amino acids in the recognition helix of the putative DNA-binding domain of FNR, with the aim of changing its specificity to that of the cyclic AMP receptor protein (CRP). In the presence of the mutant protein (FNR-215) expression of the lac operon was activated during anaerobiosis and unaffected by glucose. FNR-215 did not have a uniform effect on the expression of other cAMP-CRP-dependent genes, but the results demonstrate the fundamental similarity between FNR- and CRP-mediated transcriptional activation.
Spiro
S
S
Department of Microbiology, University of Sheffield, UK.
Guest
J R
JR
D000595:Amino Acid Sequence; D000693:Anaerobiosis; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D005796:Genes; D005798:Genes, Bacterial; D007763:Lac Operon; D008969:Molecular Sequence Data; D009154:Mutation; D001616:beta-Galactosidase / Q000235:genetics
D001426:Bacterial Proteins; D001616:beta-Galactosidase