Crystal Structure of Menin Reveals Binding Site for Mixed Lineage Leukemia (MLL) Protein.
Murai, M.J., Chruszcz, M., Reddy, G., Grembecka, J., Cierpicki, T.(2011) J Biol Chem 286: 31742-31748
- PubMed: 21757704 
- DOI: https://doi.org/10.1074/jbc.M111.258186
- Primary Citation of Related Structures:  
3RE2 - PubMed Abstract: 
Menin is a tumor suppressor protein that is encoded by the MEN1 (multiple endocrine neoplasia 1) gene and controls cell growth in endocrine tissues. Importantly, menin also serves as a critical oncogenic cofactor of MLL (mixed lineage leukemia) fusion proteins in acute leukemias. Direct association of menin with MLL fusion proteins is required for MLL fusion protein-mediated leukemogenesis in vivo, and this interaction has been validated as a new potential therapeutic target for development of novel anti-leukemia agents. Here, we report the first crystal structure of menin homolog from Nematostella vectensis. Due to a very high sequence similarity, the Nematostella menin is a close homolog of human menin, and these two proteins likely have very similar structures. Menin is predominantly an α-helical protein with the protein core comprising three tetratricopeptide motifs that are flanked by two α-helical bundles and covered by a β-sheet motif. A very interesting feature of menin structure is the presence of a large central cavity that is highly conserved between Nematostella and human menin. By employing site-directed mutagenesis, we have demonstrated that this cavity constitutes the binding site for MLL. Our data provide a structural basis for understanding the role of menin as a tumor suppressor protein and as an oncogenic co-factor of MLL fusion proteins. It also provides essential structural information for development of inhibitors targeting the menin-MLL interaction as a novel therapeutic strategy in MLL-related leukemias.
Organizational Affiliation: 
Department of Pathology, University of Michigan, Ann Arbor, Michigan 48109, USA.