On the interrelationship between atomic displacement parameters (ADPs) and coordinates in protein structures

Macromolecular models refined against X-ray diffraction data are typically described by a set of atomic coordinates and atomic displacement parameters (ADPs). Although it is intuitively obvious that the two cannot be independent of each other and although over time many attempts have been made to relate them to each other, such approaches have so far not been utilized in macromolecular structure refinement. It is demonstrated here that up to 50% of the total ADP variation in macromolecular structures may be successfully predicted solely based on the atomic coordinates and just three additional parameters per structure. This finding may have serious implications in macromolecular structure refinement, particularly at low resolution, as well as in structure validation.