Localization of the structural gene for the ' subunit of RNA polymerase in Escherichia coli

A minicell-producing strain of $\text{E.}$$\text{coli}$ carrying an F′ factor, KLF10-1, forms minicells that contain plasmid but not chromosomal DNA. These minicells were found to synthesize two polypeptides corresponding precisely to the β and β′ subunits of RNA polymerase in SDS-polyacrylamide gel electrophoresis. In contrast, minicells obtained from an isogenic strain carrying F13-1 do not synthesize these proteins under similar conditions. These results indicate that the structural genes for the β′ as well as β subunits of the polymerase are located on the chromosomal segment (78 to 81 min on the standard genetic map of $\text{E.}$$\text{coli}$) carried by KLF10-1.