PWWP Domain

**Semantic type:** Amino Acid Sequence

**Definition:** Around 70 amino acids and weakly conserved, the PWWP Domain is named after a conserved Pro-Trp-Trp-Pro motif often found as multiple copies in proteins that contain chromatin-association domains or in cell growth and differentiation transcription factors, such as WHSC1 (C-terminus) and ASH1/Trithorax Group proteins. Although its function is unknown, the amino acid composition suggests that it may be involved in protein-protein interactions. The domain N-terminal half resembles a barrel-like five-stranded structure; the C-terminal half contains a five-helix bundle. The halves form a module that exhibits positive electrostatic potential. Alone, the domain binds DNA in vitro, probably through its basic surface. (NCI)