- Yang X, Xie X, Chen L, Zhou H, Wang Z, Zhao W, Tian R, Zhang R, Tian C, Long J, Shen Y
- Structural basis for tandem L27 domain-mediated polymerization.
- FASEB J. 2010 Aug 11.
- The establishment of epithelial cell polarity requires the assembly of multiprotein complexes and is crucial during epithelial morphogenesis. Three scaffolding proteins, Dlg1, MPP7, and Mals3, can be assembled to form a complex that functions in the establishment and maintenance of apicobasal polarity in epithelial tissues through their L27 domains. Here we report the crystal structure of a 4-L27-domain complex derived from the human tripartite complex Dlg1-MPP7-Mals3 in combination with paramagnetic relaxation enhancement measurements. The heterotrimer consists of 2 pairs of heterodimeric L27 domains. These 2 dimers are asymmetric due to the large difference between the N- and C-terminal tandem L27 domain of MPP7. Structural analysis combined with biochemical experiments further reveals that the loop alphaA-alphaB and helix alphaB of the C-terminal L27 domain of MPP7 play a critical role in assembling the entire tripartite complex, suggesting a synergistic tandem L27-mediated assembling event.-Yang, X., Xie, X., Chen, L., Zhou, H., Wang, Z., Zhao, W., Tian, R., Zhang, R., Tian, C., Long, J., Shen, Y. Structural basis for tandem L27 domain-mediated polymerization.