Influence of the putative positive transcription regulator, sll1961, on apqZ expression. A, the position of sll1961 and aqpZ in the chromosomal DNA. B, WT, ΔaqpZ, Δsll1961, Δhik31, and ΔglcP cells were grown to mid-exponential phase and spotted onto solid medium without (top) or with 5 mm glucose (bottom). Each spot consisted of 5 μl of liquid culture diluted to an OD730 of 1, 0.1, or 0.01. Plates were incubated at 30 °C for 5 days. C, Western blot analysis of AqpZ protein in WT, Δsll1961, or Δhik31 cells grown in medium containing 5 mm glucose (+) or no glucose (−). D, Western blot analysis of AqpZ protein in WT and Δsll1961 cells grown in medium without glucose under low light (LL) or high light (HL) conditions.