title: Structure of the effector-binding domain of the arabinose repressor AraR from Bacillus subtilis.
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.
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, Prague 6, Czech Republic.
authors.forename: Kateřina
authors.initials: K
authors.lastname: Procházková
authors.forename: Kateřina
authors.initials: K
authors.lastname: Cermáková
authors.forename: Petr
authors.initials: P
authors.lastname: Pachl
authors.forename: Irena
authors.initials: I
authors.lastname: Sieglová
authors.forename: Milan
authors.initials: M
authors.lastname: Fábry
authors.forename: Zbyszek
authors.initials: Z
authors.lastname: Otwinowski
authors.forename: Pavlína
authors.initials: P
authors.lastname: Rezáčová
mesh_terms: D001089:Arabinose / Q000378:metabolism; D001412:Bacillus subtilis / Q000737:chemistry* / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000737:chemistry* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D012097:Repressor Proteins; D001089:Arabinose