FIG. 1.

A. Effects of H-NS deficiency and SlyA overproduction on the transcription of clyA throughout the growth curve. (A) Expression of luciferase activity from a chromosomal clyA::luxAB fusion in the strains JON33 (hns⁺) (□), JON34 (hns) (○), JON33/pACYC177 (vector control) (●), and JON33/pJON22 p(SlyA) (■). The expressed luciferase activity was quantified by the luciferase assay (see Materials and Methods), and LUX units were displayed as millivolts/(milliliters × optical density at 600 nm). The growth curves are indicated with dotted lines. (B) DNA sequence of the clyA promoter region down to 76 bp into the clyA coding sequence, which is the position of the lux and lac fusion junctions. The positions of the transcriptional initiation point (+1) and putative regulatory elements, i.e., binding sites for CRP and FNR, Shine-Dalgarno (S.D.) sequence, and −10 and −35 boxes are shown. The mutational alterations in the plasmid pMWK31 are shown in parentheses below the −10 region sequence.