PMID: 22281747 , Related PDB id: 3TB6

Authors:

Prochazkova K, Cermakova K, Pachl P, Sieglova I, Fabry M, Otwinowski Z, Rezacova P

Title:

Structure of the effector-binding domain of the arabinose repressor AraR from Bacillus subtilis.

Journal:

Acta Crystallogr D Biol Crystallogr. 2012 Feb;68(Pt 2):176-85. Epub 2012 Jan 17.

Abstract:

In Bacillus subtilis, the arabinose repressor AraR negatively controls the expression of genes in the metabolic pathway of arabinose-containing polysaccharides. The protein is composed of two domains of different phylogenetic origin and function: an N-terminal DNA-binding domain belonging to the GntR family and a C-terminal effector-binding domain that shows similarity to members of the GalR/LacI family. The crystal structure of the C-terminal effector-binding domain of AraR in complex with the effector L-arabinose has been determined at 2.2 A resolution. The L-arabinose binding affinity was characterized by isothermal titration calorimetry and differential scanning fluorimetry; the K(d) value was 8.4 +/- 0.4 microM. The effect of L-arabinose on the protein oligomeric state was investigated in solution and detailed analysis of the crystal identified a dimer organization which is distinctive from that of other members of the GalR/LacI family.