WD repEAts are motifs of approximately 40 amino acids typically terminating in conserved tryptophan and aspartate residues. Several WD40 repEAts combine to form the structural WD domain. Such an arrangement facilitates protein-protein interactions allowing the formation of multiprotein complexes.1 Human WDR5 contains seven WD 40 repEAts and was originally identified to accelerate osteoblast differentiation.2 WDR5 has been demonstrated to bind histone H3 by recognizing the first three amino acids of the N-terminal tail.3 Binding of WDR5 to a conserved arginine-containing motif in MLL-1, the so-called WDR5 interaction (Win) motif, promotes the assembly and activity of the MLL core complex.4 Additional interactions have been demonstrated with other components of the human MLL core protein complex, which includes ASH2L and RbBP5.5,6 MLL1-5 protein complexes catalyze the di- and trimethylation of histone H3 at lysine 4 (H3K4me2/me3), lEAding to the maintenance of global H3K4 trimethylation.7Technical InformationSynonymsBIG3BMP2-induced 3-kb Gene ProteinSWD3, Set1c WD40 repEAt protein, homologWD-RepEAt Protein 5Purity95% estimated by SDS-PAGESourcerecombinant protein expressed in E. coliMW34.4 kDaFormulation50 mM Tris, pH 8.0, containing 150 mM sodium chloride, 20% glycerolLicenseSUMOpro tag was used under non-exclusive license from LifeSensors, Inc.