Translational control of the expression of the beta subunit gene of E. coli RNA polymerase

Using the plasmid pNF1337 as template, a mRNA preparation has been obtained that directs the in vitro synthesis of fMet-Val, the N-terminal dipeptide of the beta subunit of RNA polymerase. RNA polymerase holoenzyme specifically inhibits the mRNA-directed synthesis of fMet-Val showing that the autoregulation by RNA polymerase of beta, beta 1 synthesis is at the level of translation. L factor (nusA gene product) stimulates the synthesis of fMet-Val from a DNA template but not from mRNA. Rifampicin has no effect on the mRNA-directed synthesis of fMet-Val or the ability of RNA polymerase to inhibit fMet-Val synthesis.