Promoters of major Escherichia coli heat shock genes seem non-functional in Bacillus subtilis.

To find out whether Escherichia coli heat shock promoters are recognized in Bacillus subtilis, the regulatory regions including the heat shock promoters of the main heat shock genes dnaKJ, lon, groES, and htpG were fused to the indicator genes lacZ and cat. Whereas all transcriptional fusions were expressed in E. coli at low temperature and transient increases of beta-galactosidase activity could be measured at the inducing temperature, no enzymatic activity was found in B. subtilis. This indicates that E. coli heat shock promoters are nonfunctional in B. subtilis.