FIG. 1.

Phosphorylation state of SprE does not regulate accumulation of RpoS in response to gradual carbon starvation. (A) Growth in glucose starvation medium is unaffected in the strain carrying sprED58A (open circles) when compared to the wild type (closed circles). Quantification of RpoS levels from the Western blot shown in panel B is shown. Solid squares, wild-type strain; open squares, mutant strain. (B) Western blot analysis of RpoS and SprE levels during gradual carbon starvation. Samples from a strain carrying either wild-type sprE or the sprED58A allele were prepared during growth in a limiting amount of glucose as described in Materials and Methods. sprE⁺ refers to strain CNP119, and sprED58A refers to CNP209 (Table 1).