4l5g

Publication Abstract from PubMed

CarD, an essential transcription regulator in Mycobacterium tuberculosis, directly interacts with the RNA polymerase (RNAP). We used a combination of in vivo and in vitro approaches to establish that CarD is a global regulator that stimulates the formation of RNAP-holoenzyme open promoter (RPo) complexes. We determined the X-ray crystal structure of Thermus thermophilus CarD, allowing us to generate a structural model of the CarD/RPo complex. On the basis of our structural and functional analyses, we propose that CarD functions by forming protein/protein and protein/DNA interactions that bridge the RNAP to the promoter DNA. CarD appears poised to interact with a DNA structure uniquely presented by the RPo: the splayed minor groove at the double-stranded/single-stranded DNA junction at the upstream edge of the transcription bubble. Thus, CarD uses an unusual mechanism for regulating transcription, sensing the DNA conformation where transcription bubble formation initiates.

Structure and function of CarD, an essential mycobacterial transcription factor.,Srivastava DB, Leon K, Osmundson J, Garner AL, Weiss LA, Westblade LF, Glickman MS, Landick R, Darst SA, Stallings CL, Campbell EA Proc Natl Acad Sci U S A. 2013 Jul 15. PMID:23858468^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.