Bacterial alkaline phosphatase clonal variation in some Escherichia coli K-12 phoR mutant strains

Control of bacterial alkaline phosphatase synthesis and variation in an Escherichia coli K-12 phoR mutant by adenyl cyclase, the cyclic AMP receptor protein, and the phoM operon.

Mutant phoR cells show a clonal variation phenotype with respect to bacterial alkaline phosphatase (BAP) synthesis. BAP clonal variation is characterized by an alternation between a Bap+ and Bap- phenotype. The switching is regulated by the phoM operon and the presence of glucose; the pho-510 mutant form of the phoM operon abolishes both BAP clonal variation and the effect of glucose (B.L. Wann...

Osmoregulation of alkaline phosphatase synthesis in Escherichia coli K-12.

Alkaline phosphatase, the phoA product, is synthesized constitutively in phoR mutants. This constitutive synthesis, which is independent of phosphate control, varies with changes in the osmolarity of the growth medium; phoA expression increases with increasing osmolarity. Maximum expression of the osmoregulated genes phoA, ompC, and ompF was achieved by osmotic manipulation of minimal medium; c...

Hfr Strains of Escherichia coli K-12

Since the first reports by Cavalli-Sforza (9) and Hayes (24) of strains of Escherichia coli K-12 which are conjugational donors of chromosomal markers at high frequency (Hfr strains), many other Hfr strains have been isolated and our understanding of the mechanisms involved in Hfr formation has increased considerably. All Hfr strains arise from the integration of a conjugative plasmid into the ...

Genetic mapping of the phoR regulator gene of alkaline phosphatase in Escherichia coli.

Strain variation in ppGpp concentration and RpoS levels in laboratory strains of Escherichia coli K-12.

Laboratory strains and natural isolates of Escherichia coli differ in their level of stress resistance due to strain variation in the level of the sigma factor sigma(S) (or RpoS), the transcriptional master controller of the general stress response. We found that the high level of RpoS in one laboratory strain (MC4100) was partially dependent on an elevated basal level of ppGpp, an alarmone res...