Comparison of a protein model with its X-ray structure: the ligand binding domain of E-selectin.

E- and P-selectin are cell adhesion molecules implicated in the early events of inflammation. Three-dimensional models of the lectin domains have been reported by us and others prior to the availability of X-ray structural information. The models have been used to outline the ligand binding site in the selectins and to identify residues critical for function. Recently, the crystal structure of E-selectin has been reported, and thus, comparison of our E-selectin model with the X-ray data is now possible. The comparison shows that the assumptions on which the modeling was based were generally correct and provides an instructive example for the opportunities and the limitations of comparative modeling.