Non-coordinate synthesis of RNA polymerase beta beta' subunits in a temperature-sensitive beta'-subunit mutant of Escherichia coli.

On exposure to high temperature of a temperature-sensitive RNA polymerase beta' subunit (rpoC92) mutant of Escherichia coli, selective reduction was observed in the rate of synthesis of a group of proteins including RNA polymerase beta' subunit. The finding that the synthesis of beta' subunit but not beta subunit was specifically repressed in this mutant grown at non-permissive temperature indicates that the functionally intact RNA polymerase is required for the synthesis of beta beta' subunits be coordinated. In addition, the assembly of newly synthesized RNA polymerase subunits was inefficient in this mutant at the steps where altered beta' subunit was involved, and the unassembled enzyme subunits were rapidly and preferentially degraded. During recovery to non-restricted growth, the synthesis of both beta and beta' subunits was transiently enhanced in parallel leading to recovery of the intracellular concentration of functional RNA polymerase.