Diversity of WD-repeat proteins.

The WD-repeat-containing proteins form a very large family that is diverse in both its function and domain structure. Within all these proteins the WD-repeat domains are thought to have two common features: the domain folds into a beta propeller; and the domains form a platform without any catalytic activity on which multiple protein complexes assemble reversibly. The fact that these proteins play such key roles in the formation of protein-protein complexes in nearly all the major pathways and organelles unique to eukaryotic cells has two important implications. It supports both their ancient and proto eukaryotic origins and supports a likely association with many genetic diseases.