Mapping of the OxyR protein contact site in the C-terminal region of RNA polymerase alpha subunit.
AUTOR(ES)
Tao, K
RESUMO
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.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=177537Documentos Relacionados
- Transcription activation at class I FNR-dependent promoters: identification of the activating surface of FNR and the corresponding contact site in the C-terminal domain of the RNA polymerase alpha subunit.
- Interdependence of Activation at rhaSR by Cyclic AMP Receptor Protein, the RNA Polymerase Alpha Subunit C-Terminal Domain, and RhaR
- Transcription initiation complexes and upstream activation with RNA polymerase II lacking the C-terminal domain of the largest subunit.
- Location of the C-terminal domain of the RNA polymerase alpha subunit in different open complexes at the Escherichia coli galactose operon regulatory region.
- Interactions of OxyR with the promoter region of the oxyR and ahpC genes from Mycobacterium leprae and Mycobacterium tuberculosis.