FIG. 4.

In vivo activation of wild-type (wt) and cbb promoter mutants. (A and B) Normalized levels of β-galactosidase activities expressed by cbbL-lacZ fusions in X. flavus H4-14 grown autotrophically (A) or heterotrophically (B). β-Galactosidase activities driven by the wild-type cbb promoter were, respectively, 7,285 and 250 nmol per min per mg of protein and were set at 100%. Empty, promoter probe vector pBC3 without an insert. (C) Normalized levels of β-galactosidase activities expressed by cbbL-lacZ fusions in X. flavus R22 grown heterotrophically. The β-galactosidase activity driven by the wild-type cbb promoter was 59 nmol per min per mg of protein and was set at 100%.