MBT Protein Repeat

Malignant Brain Tumor (MBT) repeats are putative methyl-lysine binding modules that bind methylated peptides from amino-terminal tails of H3 and H4 histones. MBT repeats are ~100 amino acid residues in length and are found in the proteome of most metazoans. Each repeat consists of a globular core and an extended arm. Interdigitation between the arms of the three MBT repeats of the polycomb group protein h-l(3)MBT results in a three-leaved propeller with a hollow central cavity. Each repeat harbors a hydrophobic, ligand-binding pocket.