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Activation of the lac Operon of Escherichia coli by a mutant FNR protein
Author(s) -
Spiro S.,
Guest J. R.
Publication year - 1987
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1987.tb00526.x
Subject(s) - operon , biology , mutant , lac operon , gal operon , escherichia coli , gene , l arabinose operon , camp receptor protein , mutagenesis , transcription (linguistics) , site directed mutagenesis , activator (genetics) , biochemistry , gene expression , microbiology and biotechnology , promoter , linguistics , philosophy
Summary 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.