malignant brain tumor (MBT) repeat found in PHD finger protein 20-like protein 1 (PHF20L1) and similar domains
PHF20L1 associates with SOX2, antagonizes SOX2 ubiquitination and the sequential degradation induced by MLL1/WDR5 complexes. It binds both monomethylated Lys-42 and Lys-117 in SOX2 and thereby prevents SOX2 proteolysis. PHF20L1 also reads and controls enzyme levels of methylated DNMT1 in cells, thus representing a novel antagonist of DNMT1 degradation. PHF20L1 contains one MBT (malignant brain tumor) repeat. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the MBT repeat of PHF20L1 and similar domains that contains the semi-aromatic cage that may bind methylated lysine residues.