Crystal structure of the arginine repressor protein in complex with the DNA operator from Mycobacterium tuberculosis

J Mol Biol. 2008 Dec 31;384(5):1330-40. doi: 10.1016/j.jmb.2008.10.015. Epub 2008 Oct 15.


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-A 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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / chemistry*
  • Crystallography, X-Ray
  • DNA, Bacterial / chemistry*
  • DNA, Bacterial / metabolism
  • Hydrogen Bonding
  • Models, Molecular
  • Molecular Sequence Data
  • Mycobacterium tuberculosis / chemistry*
  • Mycobacterium tuberculosis / genetics*
  • Operator Regions, Genetic / genetics*
  • Protein Multimerization
  • Protein Structure, Secondary
  • Repressor Proteins / chemistry*
  • Static Electricity


  • ArgR protein, Bacteria
  • Bacterial Proteins
  • DNA, Bacterial
  • Repressor Proteins

Associated data

  • PDB/3ERE