FIG. 2.

The regulatory sequence involved in heat shock regulation of htpG is located downstream of the promoter and acts in a location- and orientation-specific way. (A) Schematic representation of promoter-bgaB fusions. All fusions contain htpG promoter regions; the repeats are indicated by arrows; asterisks show nucleotide exchanges. (B) Relative β-galactosidase activities of the transcriptional fusions presented in panel A. The enzymatic activity measured with the unstressed strain SS02 was set as one relative BgaB unit (equivalent to a specific activity of 0.015 ± 0.002 U/mg of protein). The reporter enzyme activities were measured from cultures without temperature shift (light gray columns) and 30 min after a shift from 37 to 50°C (dark gray columns).