FIG. 6.
cbbI::lacZ fusions in R. sphaeroides wild-type and prrA mutant strains grown chemoautotrophically. (A) Restriction map of the cbbI promoter region, illustrating restriction sites used to make cbbI::lacZ fusions. Numbers above restriction fragments indicate the number of nucleotides from the transcriptional start site. (B) β-Galactosidase activity in cell extracts of R. sphaeroides that contained cbbI::lacZ fusions in wild-type (WT) and prrA mutant strains. Error bars indicate standard deviations.