Crystal Structure of the Arginine Repressor Protein in Complex with the DNA Operator from Mycobacterium tuberculosis

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• 作者：Leonid T. Cherney ; Maia M. Cherney ; Craig R. Garen ; George J. Lu ; Michael N.G. James
• 关键词：Mycobacterium tuberculosis ; X-ray crystallography ; arginine repressor protein ; DNA binding ; ArgR– ; operator complex
• 刊名：Journal of Molecular Biology
• 出版年：2008
• 出版时间：31 December 2008
• 年：2008
• 卷：384
• 期：5
• 页码：1330-1340
• 全文大小：2520 K

文摘

The arginine repressor (ArgR) from Mycobacterium tuberculosis (Mtb) is a gene product encoded by the open reading frame Rv1657. It regulates the l-arginine concentration in cells by interacting with ARG boxes in the promoter regions of the arginine biosynthesis and catabolism operons. Here we present a 2.5-Å structure of MtbArgR in complex with a 16-bp DNA operator in the absence of arginine. A biological trimer of the protein–DNA complex is formed via the crystallographic 3-fold symmetry axis. The N-terminal domain of MtbArgR has a winged helix–turn–helix motif that binds to the major groove of the DNA. This structure shows that, in the absence of arginine, the ArgR trimer can bind three ARG box half-sites. It also reveals the structure of the whole MtbArgR molecule itself containing both N-terminal and C-terminal domains.