Figure 8.

Space filling model of the UmuD′ dimer. In this stereo view of the UmuD′ dimer the left monomer is pale blue and the right monomer is pale green. Pairs of residues that correspond to interacting pairs of λcI amino acids are highlighted. Residues D59 and I108, which correspond to N148 and Q204 in λcI, are shown in dark blue on the left and right monomers, respectively. Residues K97 and R102, which correspond to K192 and D197 in λcI, are shown in purple on the left and right monomers, respectively. Interactions of these residue pairs at the cooperativity interface of λcI can be imagined by treating the two images as separate dimers (rather than as a stereo view) and folding them together along a vertical axis midway between them.