Genetic studies on the beta subunit of Escherichia coli RNA polymerase. VI. A redundant region in the beta polypeptide.

A single species of RNA polymerase is responsible for the transcription of genetic material in Escherichia coli; and, each component of this essential enzyme is encoded by a single gene. Nevertheless, we report the characterisation of a viable deletion mutant lacking about 165 bp in the region coding for residues 965 to 1143 of the beta subunit of this enzyme. The foreshortened beta polypeptide appears to function as normal, suggesting that this region is, in fact, non-essential with regard to the usual functions of E. coli RNA polymerase.