Correlations between calculated and experimental PRE values. Both the unliganded (A) and liganded (B) cases are shown. Each calculated PRE value is the average over the 10 lowest-PRE energy results out of 200 independent paramagnetic probe optimizations. Intradomain PREs are shown in red, interdomain in blue. Open circles involve residues 143–149, 168, 169, and 173, of which 144 is highlighted in the unliganded data sets (see text).