Download MendeleyCrystal Structure of Mo25 Alpha in Complex with the C-Terminus of the Pseudo Kinase Ste-20 Related Adaptor (Strad)
Milburn, C.C., Boudeau, J., Deak, M., Alessi, D.R., Van Aalten, D.M.F.(2004) Nat Struct Mol Biol 11: 193
- PubMed: 14730349
- DOI: https://doi.org/10.1038/nsmb716
- Primary Citation of Related Structures:
1UPK, 1UPL - PubMed Abstract:
Mouse protein 25 alpha (MO25 alpha) is a 40-kDa protein that, together with the STE20-related adaptor-alpha (STRAD alpha) pseudo kinase, forms a regulatory complex capable of stimulating the activity of the LKB1 tumor suppressor protein kinase. The latter is mutated in the inherited Peutz-Jeghers cancer syndrome (PJS). MO25 alpha binds directly to a conserved Trp-Glu-Phe sequence at the STRAD alpha C terminus, markedly enhancing binding of STRAD alpha to LKB1 and increasing LKB1 catalytic activity. The MO25 alpha crystal structure reveals a helical repeat fold, distantly related to the Armadillo proteins. A complex with the STRAD alpha peptide reveals a hydrophobic pocket that is involved in a unique and specific interaction with the Trp-Glu-Phe motif, further supported by mutagenesis studies. The data represent a first step toward structural analysis of the LKB1-STRAD-MO25 complex, and suggests that MO25 alpha is a scaffold protein to which other regions of STRAD-LKB1, cellular LKB1 substrates or regulatory components could bind.
Organizational Affiliation:
Division of Biological Chemistry & Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland.
