second Tudor domain found in Jumonji domain-containing protein 2 (JMJD2) family of histone demethylases
JMJD2 proteins, also called lysine-specific demethylase 4 histone demethylases (KDM4), have been implicated in various cellular processes including DNA damage response, transcription, cell cycle regulation, cellular differentiation, senescence, and carcinogenesis. They selectively catalyze the demethylation of di- and trimethylated H3K9 and H3K36. This model contains only three JMJD2 proteins, JMJD2A-C, which all contain jmjN and jmjC domains in the N-terminal region, followed by a canonical PHD domain, a noncanonical extended PHD domain, and tandem Tudor domains. The model corresponds to the second Tudor domain. The Tudor domain binds to proteins with dimethylated arginine or lysine residues, and may also bind methylated histone tails to facilitate protein-protein interactions. JMJD2D is not included in this model, since it lacks both the PHD and Tudor domains and has a different substrate specificity. JMJD2A-C are required for efficient cancer cell growth.