Protein Acetyltransferases Mediate Bacterial Adaptation to a Diverse Environment

Protein lysine acetylation is a conserved posttranslational modification that modulates several cellular processes. Protein acetylation and its physiological implications in eukaryotes are well understood; however, its role in bacteria is emerging. Lysine acetylation in bacteria is fine-tuned by the concerted action of lysine acetyltransferases (KATs), protein deacetylases (KDACs), and metabolic intermediates, e.g., acetyl coenzyme A (Ac-CoA) and acetyl phosphate (AcP). AcP-mediated nonenzymatic acetylation is predominant in bacteria due to its high acetyl transfer potential, whereas enzymatic acetylation by bacterial KATs (bKATs) is considered less abundant. SePat, the first bKAT discovered in Salmonella enterica, regulates the activity of the central metabolic enzyme acetyl-CoA synthetase, through its acetylation. Recent studies have highlighted the role of bKATs in stress responses like pH tolerance, nutrient stress, persister cell formation, antibiotic resistance, and pathogenesis. Bacterial genomes encode many putative bKATs of unknown biological function and significance. Detailed characterization of putative and partially characterized bKATs is important to decipher acetylation-mediated regulation in bacteria. Proper synthesis of information about the diverse roles of bKATs is missing to date, which can lead to the discovery of new antimicrobial targets in future. In this review, we provide an overview of the diverse physiological roles of known bKATs and their mode of regulation in different bacteria. We also highlight existing gaps in the literature and present questions that may help clarify the regulatory mechanisms mediated by bKATs in adaptation to a diverse habitat.