PT - JOURNAL ARTICLE AU - Qiao, Feng AU - Bowie, James U. TI - The Many Faces of SAM AID - 10.1126/stke.2862005re7 DP - 2005 May 31 TA - Science's STKE PG - re7--re7 VI - 2005 IP - 286 4099 - http://stke.sciencemag.org/content/2005/286/re7.short 4100 - http://stke.sciencemag.org/content/2005/286/re7.full SO - Sci. STKE2005 May 31; 2005 AB - Protein-protein interactions are essential for the assembly, regulation, and localization of functional protein complexes in the cell. SAM domains are among the most abundant protein-protein interaction motifs in organisms from yeast to humans. Although SAM domains adopt similar folds, they are remarkably versatile in their binding properties. Some identical SAM domains can interact with each other to form homodimers or polymers. In other cases, SAM domains can bind to other related SAM domains, to non–SAM domain–containing proteins, and even to RNA. Such versatility earns them functional roles in myriad biological processes, from signal transduction to transcriptional and translational regulation. In this review, we describe the structural basis of SAM domain interactions and highlight their roles in the scaffolding of protein complexes in normal and pathological processes.