Transcription initiation factor DksA has diverse effects on RNA chain elongation.

ABSTRACT: Bacterial transcription factors DksA and GreB belong to a family of coiled-coil proteins that bind within the secondary channel of RNA polymerase (RNAP). These proteins display structural homology but play different regulatory roles. DksA disrupts RNAP interactions with promoter DNA and inhibits formation of initiation complexes, sensitizing rRNA synthesis to changes in concentrations of ppGpp and NTPs. Gre proteins remodel the RNAP active site and facilitate cleavage of the nascent RNA in elongation complexes. However, DksA and GreB were shown to have overlapping effects during initiation, and in vivo studies suggested that DksA may also function at post-initiation steps. Here we show that DksA has many features of an elongation factor: it inhibits both RNA chain extension and RNA shorten

SUBMITTER: Furman R 

PROVIDER: S-EPMC3333854 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature