FIG 6.

Changes in chromosomal supercoiling and topA and gyrB gene expression under temperature stress conditions. (A) Analysis of the supercoiling density (σ) of the reporter pWHM3Hyg plasmid isolated from the wild-type strain exposed to 42°C for up to 120 min. (B) Relative transcription levels of the topA and gyrB genes after exposure to 42°C. The level of each gene in the control strain (i.e., wild type) was set at 100%; any changes in transcription were compared to the wild-type level. (C) Quantitative Western blot determination of the TopA level during incubation at 42°C.