Mechanism of transcription initiation at an activator-dependent promoter defined by single-molecule observation.

ABSTRACT: Understanding the pathway and kinetic mechanisms of transcription initiation is essential for quantitative understanding of gene regulation, but initiation is a multistep process, the features of which can be obscured in bulk analysis. We used a multiwavelength single-molecule fluorescence colocalization approach, CoSMoS, to define the initiation pathway at an activator-dependent bacterial σ(54) promoter that recapitulates characteristic features of eukaryotic promoters activated by enhancer binding proteins. The experiments kinetically characterize all major steps of the initiation process, revealing heretofore unknown features, including reversible formation of two closed complexes with greatly differing stabilities, multiple attempts for each successful formation of an open complex, and

SUBMITTER: Friedman LJ 

PROVIDER: S-EPMC3479156 | biostudies-literature | 2012 Feb

REPOSITORIES: biostudies-literature