Catalysis by protein acetyltransferase Gcn5

Gcn5 serves as the defining member of the Gcn5-related N-acetyltransferase (GNAT) superfamily of proteins that display a common structural fold and catalytic mechanism involving the transfer of the acyl-group, primarily acetyl-, from CoA to an acceptor nucleophile. In the case of Gcn5, the target is the ε-amino group of lysine primarily on histones. Over the years, studies on Gcn5 structure-function have often formed the basis by which we understand the complex activities and regulation of the entire protein acetyltransferase family. It is now appreciated that protein acetylation occurs on thousands of proteins and can reversibly regulate the function of many cellular processes. In this review, we provide an overview of our fundamental understanding of catalysis, regulation of activity and substrate selection, and inhibitor development for this archetypal acetyltransferase. •Gcn5 structure-function studies have often formed the basis by which we understand other HATS/KATS.•Gcn5 uses a direct attack mechanism of catalysis that involves an essential general base to facilitate acetyl transfer.•Subunits within Gcn5 complexes have roles in catalysis, substrate selection, specificity, and transcriptional activation.•Gcn5 is modulated by the cellular levels of acetyl CoA and other acyl-CoA’s and is regulated by autoacetylation.•Inhibitors that target Gcn5 have been developed as research tools and potential disease therapeutics.