Figure 1.

Classification of methyl-binding proteins (MBPs). The proteins with methyl-CpG binding abilities are broadly classified into three families based on the functional domains used for binding to methylated DNA. The “MBD-containing proteins” were the first group of MBPs to be identified and are further classified into three subfamilies (MeCP2-MBD, HMT-MBD, and HAT-MBD) based on the presence of functional domains other than MBD. The members of the HMT-MBD and HAT-MBD subfamilies have protein methyltransferase and acetylase activities respectively. The “Methyl-CpG binding Zinc finger proteins” have at least 8 members (Kaiso, ZBTB4, ZBTB38, ZFP57, KLF4, EGR1, WT1, CTCF) that can bind to methylated region using the Zinc finger motifs while the third family of MBPs consisting of UHRF1 and UHRF2 proteins uses their Set and RING-associated (SRA) domain to bind methylated DNA.