FIG 2.

Two transcription start sites (TSSs) for sat identified dependent on growth substrates. Parental and Rex_DvH mutant strains were grown in medium that would allow for sulfate respiration or pyruvate fermentation. Samples at the early-exponential-growth phase were analyzed for the TSS of sat by 5′-RACE. (A) Schematic representation of sat promoter. The predicted Rex_DvH-binding site is annotated with a yellow oval with nucleotide positions listed relative to the assumed ATG translational start codon of sat in D. vulgaris Hildenborough. Horizontal arrows denote the half-sites (inverted repeats) within the Rex_DvH-binding site. The predicted −35 site is indicated by a green box. TSSs are identified with vertical arrows (and positions) for each sample tested. (B) The Rex-binding site (underlined, highlighted in yellow) and the surrounding region is shown for the promoter sequence of sat of Desulfovibrio strains, with the predicted −35 site displayed (TTGACA, highlighted in green). A TSS (respiration) for D. vulgaris Hildenborough is highlighted in blue.