Fig. 3.
Structure of the PrfAWT-GSH-DNA complex. (A) Ribbon representation of the DNA-bound homodimer showing the binding sites of GSH at the tunnel site of each monomer. The monomers A and B are colored in gray, the HTH motif is in magenta, αD is in yellow, and the winged β-hairpin is in green. GSH is shown as sticks with the carbon atoms in crimson. The electron density covering the GSH molecules is calculated as in Fig. 1B. The 30-bp palindromic operator is shown in dark blue and orange. (B) Schematic drawing of the PrfAWT-DNA interactions. The two residues that make base-specific contacts are highlighted in red. Other contacts are nonspecific interactions between protein side chains and the DNA phosphate backbone.