Different Modes of Transactivation of Bacteriophage Mu Late Promoters by Transcription Factor C

Swapna, Ganduri and Kumari, Vandana and Nagaraja, Valakunja (2015) Different Modes of Transactivation of Bacteriophage Mu Late Promoters by Transcription Factor C. In: PLOS ONE, 10 (6).

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Abstract

Transactivator protein C is required for the expression of bacteriophage Mu late genes from lys, I, P and mom promoters during lytic life cycle of the phage. The mechanism of transcription activation of mom gene by C protein is well understood. C activates transcription at Pmom by initial unwinding of the promoter DNA, thereby facilitating RNA polymerase (RNAP) recruitment. Subsequently, C interacts with the (sic) subunit of RNAP to enhance promoter clearance. The mechanism by which C activates other late genes of the phage is not known. We carried out promoter-polymerase interaction studies with all the late gene promoters to determine the individual step of C mediated activation. Unlike at P-mom, at the other three promoters, RNAP recruitment and closed complex formation are not C dependent. Instead, the action of C at P-lys, P-I, and P-P is during the isomerization from closed complex to open complex with no apparent effect at other steps of initiation pathway. The mechanism of transcription activation of mom and other late promoters by their common activator is different. This distinction in the mode of activation (promoter recruitment and escape versus isomerization) by the same activator at different promoters appears to be important for optimized expression of each of the late genes.

Item Type:	Journal Article
Publication:	PLOS ONE
Publisher:	PUBLIC LIBRARY SCIENCE
Additional Information:	Copy right for this article belongs to the PUBLIC LIBRARY SCIENCE, 1160 BATTERY STREET, STE 100, SAN FRANCISCO, CA 94111 USA
Department/Centre:	Division of Biological Sciences > Microbiology & Cell Biology
Date Deposited:	31 Jul 2015 13:18
Last Modified:	31 Jul 2015 13:18
URI:	http://eprints.iisc.ac.in/id/eprint/51956

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