Modulation of gene expression by the product offitA gene inEscherichia coli

Physiological parameters such as viability, gross RNA synthesis,β-galactosidase induction, development of phages T4, T7 andλ have been studied in temperature-sensitiveEscherichia coli strains harbouring fit A76,fit A24 andfit A76fit A24 mutations in rpoB⁺ andrpoB240 genetic backgrounds. The efficiently of expression of these functions is influenced by thefit A alleles depending upon the medium of growth and/or temperature. Strains harbouring therpoB240 mutation and thefit A76 mutation, either alone or together with thefit A24 mutation, are rifampicin-sensitive even at the perfssive temperature. The results suggest possible interaction between thefit A gene product and RNA polymerase invivo. This paper is dedicated to Proof. S. Krishnaswamy on his Sixty First Birthday.