The PWWP domain is part of BS69 protein, a nuclear protein that specifically binds adenoviral E1A and Epstein-Barr viral EBNA2 proteins, suppressing their transactivation functions. BS69 is a multi-domain protein, containing bromo, PHD, PWWP, and MYND domains. The specific role of the PWWP domain within BS69 is not clearly identified, but BS69 functions in chromatin remodeling, consistent with other PWWP-containing proteins. The PWWP domain, named for a conserved Pro-Trp-Trp-Pro motif, is a small domain consisting of 100-150 amino acids. The PWWP domain is found in numerous proteins that are involved in cell division, growth and differentiation. Most PWWP-domain proteins seem to be nuclear, often DNA-binding, proteins that function as transcription factors regulating a variety of developmental processes.