FIG. 3.
(A) The O2R element contains a 5′-GATAA-3′ sequence (arrow) on the complementary strand. (B) The 5′-GATAA-3′ sequence plays an important role in O2 repression. Dotted box, O2R element (nt −356 to −307); solid box, O2R in which the 5′-GATAA-3′ sequence is changed to 5′-ACGCC-3′ by site-directed mutagenesis. The conditions used for measurement of rAPase activity in cells of the wild-type strain (SH5143) harboring the respective reporter genes and the symbols employed are as described in the legend to Fig. 2.