GO:0071987

Interacting selectively and non-covalently with a WD40 repeat domain of a protein. The WD40 repeat is a short structural motif of approximately 40 amino acids, often terminating in a tryptophan-aspartic acid (W-D) dipeptide. Several of these repeats are combined to form a type of protein domain called the WD domain. [GOC:yaf, InterPro:IPR017986]