The L3 loop and C-terminal phosphorylation jointly define Smad protein trimerization.
Chacko, B.M., Qin, B., Correia, J.J., Lam, S.S., de Caestecker, M.P., Lin, K.(2001) Nat Struct Biol 8: 248-253
- PubMed: 11224571 
- DOI: 10.1038/84995
- Primary Citation of Related Structures:  
1G88 - PubMed Abstract: 
Smad proteins mediate the transforming growth factor beta responses. C-terminal phosphorylation of R-Smads leads to the recruitment of Smad4 and the formation of active signaling complexes. We investigated the mechanism of phosphorylation-induced Smad complex formation with an activating pseudo-phosphorylated Smad3 ...