Skip to main content
Article thumbnail
Location of Repository

Mapping of the OxyR protein contact site in the C-terminal region of RNA polymerase alpha subunit.

By K Tao, C Zou, N Fujita and A Ishihama


The Escherichia coli OxyR protein requires the C-terminal contact site I region of the RNA polymerase alpha subunit for cooperative interaction with and transcription activation at OxyR-dependent promoters, suggesting direct protein-protein contact between OxyR and the C-terminal region of the alpha subunit. To determine the precise location of the OxyR protein contact site(s) in this region, we carried out mutational analysis of the 3' half of E. coli rpoA, the gene encoding the alpha subunit of RNA polymerase. We isolated a number of rpoA mutants defective in oxyR-dependent transcription activation at the E. coli katG promoter. Nucleotide sequence analysis of the rpoA gene from these mutants revealed that the mutations showing clear phenotypes are all clustered at two narrow regions (amino acid residues 265 to 269 and 293 to 300) within the C terminus of the alpha subunit. Reconstituted RNA polymerases containing the mutant alpha subunits were unable to respond to transcription activation in vitro at the katG, ahpC, and oxyX promoters by OxyR. These results suggest that these two regions comprise the contact surfaces on the alpha subunit for OxyR

Topics: Research Article
Year: 1995
OAI identifier:
Provided by: PubMed Central
Sorry, our data provider has not provided any external links therefore we are unable to provide a link to the full text.

Suggested articles

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.