On the role of the Escherichia coli RNA polymerase σ70 region 4.2 and α-subunit C-terminal domains in promoter complex formation on the extended -10 galP1 promoter

Leonid Minakhin, Konstantin Severinov

Research output: Contribution to journalArticlepeer-review

36 Citations (Scopus)

Abstract

Bacterial promoters of the extended -10 class contain a single consensus element, and the DNA sequence upstream of this element is not critical for promoter activity. Open promoter complexes can be formed on an extended -10 Escherichia coli galP1 promoter at temperatures as low as 6 °C, when complexes on most promoters are closed. Here, we studied the contribution of upstream contacts to promoter complex formation using galP1 and its derivatives lacking the extended -10 motif and/or containing the -35 promoter consensus element. A panel of E. coli RNA polymerase holoenzymes containing two, one, or no a-subunit C-terminal domains (αCTD) and either wild-type σ70 subunit or σ70 lacking region 4.2 was assembled and tested for promoter complex formation. At 37 °C, αCTD and σ70 region 4.2 were individually dispensable for promoter complex formation on galP1 derivatives with extended -10 motif. However, no promoter complexes formed when both αCTD and σ70 region 4.2 were absent. Thus, in the context of an extended -10 promoter, αCTD and σ70 region 4.2 interactions with upstream DNA can functionally substitute for each other. In contrast, at low temperature, αCTD and σ70 region 4.2 interactions with upstream DNA were found to be functionally distinct, for σ70 region 4.2 but not αCTD was required for open promoter complex formation on galP1 derivatives with extended -10 motif. We propose a model involving σ70 region 4.2 interaction with the β flap domain that explains these observations.

Original languageEnglish
Pages (from-to)29710-29718
Number of pages9
JournalJournal of Biological Chemistry
Volume278
Issue number32
DOIs
Publication statusPublished - 8 Aug 2003
Externally publishedYes

Fingerprint

Dive into the research topics of 'On the role of the Escherichia coli RNA polymerase σ70 region 4.2 and α-subunit C-terminal domains in promoter complex formation on the extended -10 galP1 promoter'. Together they form a unique fingerprint.

Cite this