Heat shock and cold shock genes segregate into supercoiling-responsive profiles. A total of 32 temperature stress genes were selected from the 2146 genes above noise as defined by Blattner notation (Blattner et al. 1997), GenProtEC (Karp et al. 2002), and EcoGene (Rudd 2000). Genes were partitioned into two clusters using the conditions denoted in Fig.2. (A) Expression profiles for novobiocin (N) and salt (S) conditions are plotted. (B) The distribution of cold shock and heat shock genes are shown for each cluster.