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 Å 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 μM. 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.
Original language | English (US) |
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Pages (from-to) | 176-185 |
Number of pages | 10 |
Journal | Acta Crystallographica Section D: Biological Crystallography |
Volume | 68 |
Issue number | 2 |
DOIs | |
State | Published - Feb 2012 |
Keywords
- differential scanning fluorimetry
- dimeric interface
- dimerization
- effector binding
- isothermal titration calorimetry
- repressors
ASJC Scopus subject areas
- Structural Biology