Crystal Structure of multidrug binding protein QacR from Staphylococcus aureus cocrystallized with compound DB75

Multidrug-Binding Transcription Factor QacR Binds the Bivalent Aromatic Diamidines DB75 and DB359 in Multiple Positions

Mother liquor consists of 2.3 -2.7M ammonium sulfate and 0.1M sodium acetate. The protein stock solution is 10mg/mL and is mixed with a 1:1 dilution with the mother liquor. The ligand is added to the protein stock solution at concentrations of 200-500 micromolar., pH 4.6, VAPOR DIFFUSION, HANGING DROP, temperature 298K

DB75 ligand is disordered.
The A and B chains and D and E chains form two distinct dimers. The A and B dimer assumes the drug bound conformation. The D and E dimer assumes the apo conformation.

MULTIDRUG RECOGNITION, DB75, QACR, MULTIDRUG BINDING PROTEIN, TRANSCRIPTION