second Tudor domain found in AT-rich interactive domain-containing protein 4B (ARID4B) and similar proteins
ARID4B, also called 180 kDa Sin3-associated polypeptide (p180), breast cancer-associated antigen BRCAA1, histone deacetylase complex subunit SAP180, or retinoblastoma-binding protein 1-like 1 (RBP1L1 or RBBP1L1), is a leukemia and tumor suppressor involved in epigenetic regulation in leukemia and Prader-Willi/Angelman syndromes. It associates with the mSIN3A histone deacetylase (HDAC) chromatin remodeling complex through its interaction with the breast cancer associated tumor suppressor ING1, the breast cancer metastasis suppressor BRMS1, and ARID4A ( also known as RBP1). ARID4B plays a causative role in metastatic progression of breast cancer. It may also be associated with regulating the cell cycle. ARID4B contains tandem Tudor domains, a PWWP domain (also known as HATH domain or RBB1NT domain), an AT-rich DNA-interacting domain (ARID, also known as BRIGHT), a chromobarrel domain, and a C-terminal R2 domain. 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.