A comparison of refined X-ray structures of hydrogenated and perdeuterated rat γE-crystallin in H2O and D2O

Rat γE-crystallin was overexpressed, purified under different labelling conditions and crystallized and X-ray data were collected at resolutions between 1.71 and 1.36 A. The structures were determined by molecular replacement. In these structures, the cd loop of the Greek-key motif 3, which is the major structural key motif of the two phase-transition groups of γ-crystallins, presents a double conformation. The influence of the perdeuteration on the protein structure was determined by comparison of the atomic positions and temperature factors of the different models. The perdeuterated proteins have a similar structure to their hydrogenated counterparts, but partial or full deuteration may have some effect on the atomic B-factor values.