title: [The multifunctional fructose-specific component of the phosphoenolpyruvate-dependent phosphotransferase system of Escherichia coli K12--fruA gene product].
abstract: Mutational damage of the ptsH gene leads to pleiotropic disturbance of sugar utilization in Escherichia coli K12. A fruS mutation suppresses the defect because of a constitutional expression of the fruB and fruA genes. FruB protein possessing a pseudo-HPr activity replaces the HPr. It was shown that wild type allele fruS+ dominates over the fruS1156 mutation in heterozygous merodiploid. The existence of thermosensitive mutations (fruS4 and fruS12) which repair the ptsH damage was also demonstrated. The fruS mutations were located in the fru operon. Fructose utilization was not disturbed in fruS1156 mutant, but fruS2 and fruS12 mutants were unable to utilize fructose. Spontaneous mutations (fruS6 and fruS13) possessing the same phenotype at any temperature similar to the thermosensitive ones under nonpermissive conditions were isolated. They were mapped using the P1vir transduction. The fruS mutations were found in the structural gene of the fructose operon. Presumably it is the fruA gene that cods for the fructose-specific multidomain protein IIB'Bc of the phosphoenolpyruvate-dependent phosphotransferase system.
authors.affiliation: N. F. Gamaleya Institute of Epidemiology and Microbiology, Russian Academy of Medical Sciences.
authors.forename: O Iu
authors.initials: OIu
authors.lastname: Dobrynina
authors.forename: R S
authors.initials: RS
authors.lastname: Erlagaeva
authors.forename: A M
authors.initials: AM
authors.lastname: Umiarov
authors.forename: T N
authors.initials: TN
authors.lastname: Bol'shakova
mesh_terms: D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D005632:Fructose / Q000378:metabolism*; D005798:Genes, Bacterial; D006579:Heterozygote; D009154:Mutation; D010641:Phenotype; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000235:genetics* / Q000502:physiology
chemical_list: D005632:Fructose; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System