A Transcript Cleavage Factor of Mycobacterium tuberculosis Important for Its Survival

China, Arnab and Mishra, Sonakshi and Nagaraja, Valakunja (2011) A Transcript Cleavage Factor of Mycobacterium tuberculosis Important for Its Survival. In: PLos One, 6 (7).

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Abstract

After initiation of transcription, a number of proteins participate during elongation and termination modifying the properties of the RNA polymerase (RNAP). Gre factors are one such group conserved across bacteria. They regulate transcription by projecting their N-terminal coiled-coil domain into the active center of RNAP through the secondary channel and stimulating hydrolysis of the newly synthesized RNA in backtracked elongation complexes. Rv1080c is a putative gre factor (MtbGre) in the genome of Mycobacterium tuberculosis. The protein enhanced the efficiency of promoter clearance by lowering abortive transcription and also rescued arrested and paused elongation complexes on the GC rich mycobacterial template. Although MtbGre is similar in domain organization and shares key residues for catalysis and RNAP interaction with the Gre factors of Escherichia coli, it could not complement an E. coli gre deficient strain. Moreover, MtbGre failed to rescue E. coli RNAP stalled elongation complexes, indicating the importance of specific protein-protein interactions for transcript cleavage. Decrease in the level of MtbGre reduced the bacterial survival by several fold indicating its essential role in mycobacteria. Another Gre homolog, Rv3788 was not functional in transcript cleavage activity indicating that a single Gre is sufficient for efficient transcription of the M. tuberculosis genome.

Item Type:	Journal Article
Publication:	PLos One
Publisher:	Public Library of Science
Additional Information:	Copyright of this article belongs to Public Library of Science.
Department/Centre:	Division of Biological Sciences > Microbiology & Cell Biology
Date Deposited:	03 Aug 2011 06:26
Last Modified:	03 Aug 2011 06:26
URI:	http://eprints.iisc.ac.in/id/eprint/39602

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