FIG. 7.

Fifty conserved nucleotides contain the three elements required for Dam- and OxyR-dependent expression. In panel A, an overview of the regulatory region is given. Symbols are as described for Fig. 4. In panel B, the DNA sequence of the required 101-nt region is shown. The −10 and −35 regions of the promoter are shaded, and the GATC Dam target sequences are bold and capitalized. Row 1 (K12), shared sequence between MV301 and MV500; row 2 (mot), binding motif for the reduced form of OxyR, from Kullik et al. (24); row 3 (oxybs), DNase I footprint with OxyR(C199S) (Fig. 2) indicated by a hatched bar (∗, DNase I hypersensitive site); row 4 (cons), nucleotides conserved between rows 1, 5, 6, and 7 (underlined nucleotides are conserved only between rows 1 and 5); rows 5 to 8, sequences from E. coli RS218 (RS), S. flexneri (AF200692) (1) (sh), E. coli O157: H7 (O157) (AE005174) (31), and phage Mu (Mu) (V01463) (20), respectively (see text).