FIG. 1.

Effects of mutations on fmgBC promoter activity in vivo and on DNA binding in vitro. The top part of the figure shows a summary of mutational effects on developmental fmgB-lacZ expression (67). The wild-type fmgBC upstream sequence is alternately boxed or underlined to indicate changed sequences, which are shown below the downward arrows. The number beneath each mutant sequence indicates the maximum β-galactosidase activity during development, expressed as a percentage of the maximum activity observed for the wild-type promoter. The bottom part shows EMSAs performed with ³²P-labeled fmgBC DNA (12 nM) spanning from positions −104 to −29 and proteins in the AS fraction (0.7 μg/μl). The arrow indicates the shifted complex produced by incubating the wild-type (WT) DNA fragment with the AS fraction. No complex was observed with a DNA fragment bearing the indicated mutation at positions −67 to −64.