Open AccessStructure of the C‐terminal effector‐binding domain of AhrC bound to its corepressor l ‐arginine
Author(s) -
Garnett James A.,
Baumberg Simon,
Stockley Peter G.,
Phillips Simon E. V.
Publication year - 2007
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309107049391
Subject(s) - corepressor , repressor , random hexamer , operon , biochemistry , arginine , activator (genetics) , transcription (linguistics) , biology , transcription factor , chemistry , gene , amino acid , escherichia coli , linguistics , philosophy
The arginine repressor/activator protein (AhrC) from Bacillus subtilis belongs to a large family of multifunctional transcription factors that are involved in the regulation of bacterial arginine metabolism. AhrC interacts with operator sites in the promoters of arginine biosynthetic and catabolic operons, acting as a transcriptional repressor at biosynthetic sites and an activator of transcription at catabolic sites. AhrC is a hexamer of identical subunits, each having two domains. The C‐terminal domains form the core of the protein and are involved in oligomerization and l ‐arginine binding. The N‐terminal domains lie on the outside of the compact core and play a role in binding to 18 bp DNA operators called ARG boxes. The C‐terminal domain of AhrC has been expressed, purified and characterized, and also crystallized as a hexamer with the bound corepressor l ‐arginine. Here, the crystal structure refined to 1.95 Å is presented.