Alteration intemplate recognition by Escherichia coli RNA polymerase lacking the ωsubunit: A mechanisitc analysis through gel retardation and foot-printing studies

摘要

The ω subunit of Escherichia coli RNA polymerase is a 91 amino acid polypeptide which co-purifies with the enzyme and is thought to help in maturing the rest of the enzyme to its full functionality . Purified ω when added externally was found to inhiit general transcriptional activity of ω-less RNA polymerase as well as promoter- specific single-round transcriptional activity at all the promoters tested. In this study we have tried to analyse the observed inhibition of transcription using gel retardation assays and KMnO_4 foot-printing. Further, through protein foot-printingwe have attempted to identify alterations in the interaction of the ω-less core enzyme with the σ~70 subunit.