Methyl-Lysine Binding: Malignant Brain Tumor Repeat

Structure of three MBT repeats of lethal malignant brain tumor.

Domain Binding and Function

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.

Structure Reference

  1. Wang, W. K. et al. (2003) Structure 11, 775–789.

Examples of Domain Proteins

Methyl-Lysine Binding: Malignant Brain Tumor Repeat

Binding Examples

MBT Protein Binding Partner
CGI-72 monomethylated histone H3 lysine-4 or H4 lysine-20
L(3)MBTL Histone H3 monomethylated lysine-4