Comparison of promoter-specific events during transcription initiation in mycobacteria

China, Arnab and Tare, Priyanka and Nagaraja, Valakunja (2010) Comparison of promoter-specific events during transcription initiation in mycobacteria. In: Microbiology, 156 (Part 7). pp. 1942-1952.

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Abstract

DNA protein interactions that occur during transcription initiation play an important role in regulating gene expression. To initiate transcription, RNA polymerase (RNAP) binds to promoters in a sequence-specific fashion. This is followed by a series of steps governed by the equilibrium binding and kinetic rate constants, which in turn determine the overall efficiency of the transcription process. We present here the first detailed kinetic analysis of promoter RNAP interactions during transcription initiation in the sigma(A)-dependent promoters P-rrnAPCL1, P-rrnB and P-gyr of Mycobacterium smegmatis. The promoters show comparable equilibrium binding affinity but differ significantly in open complex formation, kinetics of isomerization and promoter clearance. Furthermore, the two rrn promoters exhibit varied kinetic properties during transcription initiation and appear to be subjected to different modes of regulation. In addition to distinct kinetic patterns, each one of the housekeeping promoters studied has its own rate-limiting step in the initiation pathway, indicating the differences in their regulation.

Item Type:	Journal Article
Publication:	Microbiology
Publisher:	Society for General Microbiology
Additional Information:	Copyright of this article belongs to Society for General Microbiology.
Department/Centre:	Division of Biological Sciences > Microbiology & Cell Biology
Date Deposited:	09 Aug 2010 10:01
Last Modified:	19 Sep 2010 06:13
URI:	http://eprints.iisc.ac.in/id/eprint/31205

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