[ptsS: a new regulatory element of the fructose operon in Escherichia coli].

Expression of catabolite sensitive operons is repressed in E. coli mutants devoid of HPr--a component of glucose transport system. The ptsH mutants do not utilize the substrates for phosphoenolpyruvate dependent phosphotransferase system (PTS) except for fructose. Besides that, the mutants are deficient in utilization of many substrates entering the bacteria via the other transport systems. The ptsS mutation mapped in the region of the fructose regulon on the 46th min of the chromosomal map restores the growth of ptsH mutants on all substrates. The accumulation and PEP-dependent phosphorylation of proteins substrates of PTS is also restored. The synthesis of the fructose specific phosphotransferase system becomes constitutive under the effect of ptsS mutation. The mutation is supposed to impair the regulatory region of the fructose regulon.