FIG. 2.
MprA directly binds upstream regions of stress-responsive sigma factors. 32P-labeled DNA from the sigB (A), sigE (B), and sigH (C) upstream regions were incubated with His-MprA∼P and used in EMSAs. Seven nanograms of labeled DNA was used in all binding reaction mixtures. Labeled DNA was incubated in the absence (lane 1) or presence (lanes 2 to 8) of 0.44 to 35.0 pmol wild-type His-MprA∼P. Binding specificity was determined by incubation of labeled DNA (lane 9) with 6 pmol His-MprA∼P in the absence (lane 10) or presence of a 150-fold excess of cold DNA from either the mprA upstream region (lane 11) or PPE19 upstream region (lane 12). Labeled DNA was also incubated with 14 pmol of the phosphorylation-deficient His-MprA(D48A) mutant (lane 13). F, free DNA; B, bound DNA.