FIG. 1.

Complementation of a phoB mutant with PhoB restores polyP accumulation. Wild-type E. coli MG1655 (A), a corresponding phoB::Tn5 mutant, and the mutant complemented with a phoB plasmid (phoB*) (B) were grown in MOPS-buffered minimal medium containing 0.1 mM P_i (20 μCi of ³²P_i per ml) and 2 μg of each of the 20 amino acids per ml. Cultures (1 ml) were sampled for measurement of growth and polyP content (see Materials and Methods). Growth (OD) and polyP accumulation (PolyP) of the wild type (A) and of the phoB::Tn5 and plasmid-complemented phoB::Tn5 strains (B) are shown.