Maximal B-factors in protein crystal structures

Since the contribution of proteins atoms with exceptionally large B-factors, much larger than those of other atoms, to the observed structure factors is negligible, it is therefore recommended to consider with a care the parts of the models where B-factors are inflated to extremely large values. Otherwise, molecular biologists risk to over-interpret structural data, since the positions of these atoms is highly uncertain. In the present communication, maximal B-factor values, over which the atoms can be considered 'invisible', are estimated based on the relationships between B-factors and solvent accessible surface areas.