Biochemical and genetic analysis of Salmonella enterica pat, a multidomain, multimeric N(epsilon)-lysine acetyltransferase involved in carbon and energy metabolism

Nepsilon-lysine (N epsilon-Lys) acetylation is the transfer of an acetyl group from acetyl-coenzyme A (Ac-CoA) to a lysyl residue of a target protein or small molecule. This modification was first reported and has been extensively studied in eukaryotes, but now has emerged as a likely general mode of posttranslational regulation in prokaryotes. In prokaryotes, lysine acetylation/deacetylation has been shown to regulate the activity of acyl-CoA synthetases (AMP-forming). In Salmonella enterica, the pat gene encodes the acetyl-CoA-dependent protein acetyltransferase that modifies Acs by acetylation, and cobB encodes the NAD+-dependent sirtuin deacetylase that removes the acetyl moiety from Pat-modified Acs. Salmonella Acs was the first metabolic enzyme as well as the first bacterial protein reported to be modified by Nepsilon-Lys acetylation. This dissertation focuses on the characterization of the Pat enzyme using both biochemical and genetic means for the eventual goal of expanding our understanding of the role of Nepsilon-Lys acetylation in prokaryotic cell physiology.