Abstract
Transcription activation by the Escherichia coli cyclic AMP receptor protein (CRP) at different promoters has been studied using RNA polymerase holoenzyme derivatives containing two full-length alpha subunits, or containing one full-length alpha subunit and one truncated alpha subunit lacking the alpha C-terminal domain (alpha CTD). At a promoter having a single DNA site for CRP, activation requires only one full-length alpha subunit. Likewise, at a promoter having a single DNA site for CRP and one adjacent UP-element subsite (high-affinity DNA site for alpha CTD), activation requires only one full-length alpha subunit. In contrast, at promoters having two DNA sites for CRP, or one DNA site for CRP and two UP-element subsites, activation requires two full-length alpha subunits. We conclude that a single copy of alpha CTD is sufficient to interact with one CRP molecule and one adjacent UP-element subsite, but two copies of alpha CTD are required to interact with two CRP molecules or with one CRP molecule and two UP-element subsites.
Original language | English |
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Pages (from-to) | 2557-2565 |
Number of pages | 9 |
Journal | Genes & Development |
Volume | 16 |
Issue number | 19 |
DOIs | |
Publication status | Published - 1 Oct 2002 |
Keywords
- CRP-dependent promoters
- RNA polymerase alpha subunit
- cAMP receptor protein
- transcription activation