Figure 1. Kullback-Leibler Divergence highlights PDK1 regions that show protection in hydrogen-deuterium exchange experiments upon addition of an allosteric small molecule activator.
(Left) A small molecule activator of PDK1 was previously shown to protect various peptide regions (each shown in a different color) from hydrogen-deuterium exchange. Note that the resolution of the HDX experiments is at the peptide-level, and reflect both fast and slow motions, up to the minute time-scale. (Right) Local Kullback-Leibler Divergence values between the apo and allosteric activator-bound ensembles are mapped onto the structure using PyMOL’s “β-factor putty” preset. White indicates statistically insignificant divergence, and significant divergence values increase from blue to red. Most of the regions showing protection upon ligand binding also show statistically significant K-L divergence values.