WD repeat-containing proteins

WD repeat-containing proteins (WDRs) are a class of regulatory proteins that contain four or more repeating WD units. The WD motif, also known as the Trp-Asp or WD40 motif, is a short structural motif of approximately 40 amino acids that is often bordered by glycine-histidine and tryptophan-aspartic acid (WD) dipeptides. Tandem copies of these repeats typically fold together to form a type of circular solenoid protein domain called the WD40 domain.