The PWWP domain is an essential part of the Hepatoma Derived Growth Factor (HDGF) family of proteins, and is necessary for DNA binding by HDGF. This family of endogenous nuclear-targeted mitogens includes HRP (HDGF-related proteins 1, 2, 3, 4, or HPR1, HPR2, HPR3, HPR4, respectively) and lens epithelium-derived growth factor, LEDGF. Members of the HDGF family have been linked to human diseases, and HDGF is a prognostic factor in several types of cancer. 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.
Comment:Possible chromatin binding property is supported by its charasteristic electrostatic charge distribution. Upon binding, the charged surfaces may form nonspecific contacts with the nucleic acid on the basic side and contact the core histone molecules along the acidic surface.