Mbt Domain Containing Protein 1 (MBTD1)

The respective members function as large protein complexes involved in establishment and maintenance of transcriptional repression of developmental control genes. MBTD1, Malignant Brain Tumor domain-containing protein 1, is one such PcG protein. MBTD1 contains four MBT repeats. The crystal structure of MBTD1 reveals its similarity to another four-MBT-repeat protein L3MBTL2, which binds lower methylated lysine histones. MBTD1 preferentially binds mono- and di-methyllysine histone peptides, like L3MBTL1 and L3MBTL2. The four MBT repeats in MBTD1 exhibits an asymmetric rhomboid architecture. Like other MBT repeat proteins characterized so far, MBTD1 binds mono- or dimethylated lysine histones through one of its four MBT repeats utilizing a semi-aromatic cage.