Effect of glpT and glpD mutations on expression of the phoA gene in Escherichia coli.
In vivo 31P nuclear magnetic resonance analysis of Escherichia coli cells showed that the intracellular concentration of P(i) remained constant in wild-type and in a glpT mutant strain whether the cells were grown on excess (2 mM) P(i) or sn-glycerol-3-phosphate as a phosphate source. The function of the phoA promoter (measured by beta-galactosidase activity in a phoA-lacZ fusion strain) was repressed when glpT+ cells were utilizing sn-glycerol-3-phosphate as the sole source of phosphate. These cells were devoid of alkaline phosphatase activity. However, the phoA promoter was fully active in a glpT mutant. These results indicated that the repression of the enzyme synthesis was not due to a variation in the level of cytoplasmic P(i) but was due to the P(i) excreted into the periplasm and/or to the medium.
Rao
N N
NN
Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.
Roberts
M F
MF
Torriani
A
A
Yashphe
J
J
D000469:Alkaline Phosphatase / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics*; D004794:Enzyme Repression; D004926:Escherichia coli / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics*; D005988:Glyceric Acids / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D009154:Mutation; D010710:Phosphates / Q000378:metabolism; D010712:Phosphatidic Acids / Q000378:metabolism; D010759:Phosphorus Isotopes; D011401:Promoter Regions, Genetic / Q000235:genetics; D011993:Recombinant Fusion Proteins; D001616:beta-Galactosidase / Q000096:biosynthesis / Q000235:genetics
D001426:Bacterial Proteins; D005988:Glyceric Acids; D010710:Phosphates; D010712:Phosphatidic Acids; D010759:Phosphorus Isotopes; D011993:Recombinant Fusion Proteins; C005156:3-phosphoglycerate; D000469:Alkaline Phosphatase; D001616:beta-Galactosidase