Fructose-specific phosphoenolypyruvate dependent phosphotransferase system of Escherichia coli : Its alterations and adenylate cyclase activity

The authors found that mutational damage of EIII super(fru) (fruB mutation) results in decrease of adenylate cyclase (AC) activity in E. coli cells that causes reduction of the lac operon expression. Their data confirm the suggestion that some, or all, of enzymes involved in the regulation of AC by the PTS. The question about the existence of a high basal level of the EIII super(fru) has arisen, since the effect of the fruB mutation on AC activity was demonstrated in cells grown in media without fructose. In the present paper, the assessment of the basal level of the fru regulon proteins is being dealt with using fru-lacZ fusions.