A high-resolution structure of the DNA-binding domain of AhrC, the arginine repressor/activator protein from Bacillus subtilis.
In Bacillus subtilis the concentration of L-arginine is controlled by the transcriptional regulator AhrC, which interacts with 18 bp DNA operator sites called ARG boxes in the promoters of arginine biosynthetic and catabolic operons. AhrC is a 100 kDa homohexamer, with each subunit having two domains. The C-terminal domains form the core, mediating intersubunit interactions and binding of the co-repressor L-arginine, whilst the N-terminal domains contain a winged helix-turn-helix DNA-binding motif and are arranged around the periphery. The N-terminal domain of AhrC has been expressed, purified and characterized and it has been shown that the fragment still binds DNA operators as a recombinant monomer. The DNA-binding domain has also been crystallized and the crystal structure refined to 1.0 A resolution is presented.
Garnett
James A
JA
Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, England.
Baumberg
Simon
S
Stockley
Peter G
PG
Phillips
Simon E V
SE
D001120:Arginine / Q000378:metabolism; D001412:Bacillus subtilis / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray; D004268:DNA-Binding Proteins / Q000737:chemistry*; D008958:Models, Molecular; D017433:Protein Structure, Secondary; D012097:Repressor Proteins / Q000737:chemistry*; D015534:Trans-Activators / Q000737:chemistry*
C120339:AhrC protein, Bacillus subtilis; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D012097:Repressor Proteins; D015534:Trans-Activators; D001120:Arginine