Structural Basis for Sirtuin Activity and Inhibition*

Sir2 proteins, or sirtuins, are a family of enzymes that catalyze NAD⁺-dependent deacetylation reactions and can also process ribosyltransferase, demalonylase, and desuccinylase activities. More than 40 crystal structures of sirtuins have been determined, alone or in various liganded forms. These high-resolution architectural details lay the foundation for understanding the molecular mechanisms of catalysis, regulation, substrate specificity, and inhibition of sirtuins. In this minireview, we summarize these structural features and discuss their implications for understanding sirtuin function.