Modulation of gene expression by the product of fitA gene in Escherichia coli.

Physiological parameters such as viability, gross RNA synthesis, β-galactosidase induction, development of phages T4, T7 and λ have been studied in temperature-sensitive Escherichia coli strains harbouring fit A76, fit A24 and fit A76fit A24 mutations in rpoB+ and rpoB240 genetic backgrounds. The efficiently of expression of these functions is influenced by the fit A alleles depending upon the medium of growth and/or temperature. Strains harbouring the rpoB240 mutation and the fit A76 mutation, either alone or together with the fit A24 mutation, are rifampicin-sensitive even at the perfssive temperature. The results suggest possible interaction between the fit Α gene product and RNA polymerase in vivo.