Fig. 3.

The CATS conformational space for a mutant of the antibody VRC07 includes non-clashing conformations inaccessible to rigid-backbone design. The backbone was either held rigid (A) or allowed DEEPer (Hallen et al., 2013) (B) or CATS (C) flexibility for five residues. (A–C) Steric clashes between atoms indicated in pink. (D) The three designs overlaid (rigid backbone in magenta, DEEPer in cyan, CATS in green). (E) Broader view: 15 residues (green, yellow, pink) were allowed continuous sidechain flexibility, of which ten were restrained in an ${({18}^{°})}^n$-continuous rotamer voxel centered on the original rotamer (n = number of sidechain dihedrals); the segment with backbone flexibility is shown in yellow, and Trp 54 in pink. Designs were run starting from PDB id 4OLX (Rudicell et al., 2014)