Allosteric Regulation Of ACT-GNAT Acetyltransferases By Amino Acid Molecules

Reversible lysine acetylation of proteins is a ubiquitous conserved protein post-translational modification that means for the rapid control of diverse cellular processes and cellular signaling.To date,prokaryotic reversible lysine acetylation?RLA?systems have been studied in a few bacteria,but little is known about RLA in antibiotic-producing actinomycetes.Now 156 proteins with ACT-Gcn5-related N-acetyltransferase?GNAT?domain organization were found in actinomycetales.Here we select the 24 proteins to analysis their enzyme activity by different Amino acids and their regulatory mechanism with acetyl-CoA synthetase?Acs?.ACT domains as Amino acid-binding domains are linked to a large-scale of metabolic enzymes,which are responded to Amino acid concentrations.In this study,Amino acids were screen as ligands by measuring the active changes that occur upon Amino acid binding to the ACT domain in the PatA proteins using the continuous spectrophotometric assays at 340 nm.We found that the vast majority of Pat A proteins can combine with asparagine or cysteine specifically.In this study,we further investigate a Gcn5-related N-acetyltransferase containing N-terminal ACT domain,Amir₅672?AmiPatA?,from Actinosynnema mirum strain DSM 43827.Cysteine?Cys?was identified as a ligand by measuring the active changes that occur upon Amino acid binding to the ACT domain in the AmiPatA protein using the continuous enzymatic assays and western blotting.We found that AmiPatA is an Amino acid-regulated protein acetyltransferase for the reason of Cys stimulated the activity of AmiPatA on acetylation of acetyl-CoA synthetase?Amir₀262?,AmiAcs.Cys was identified as ligands by monitoring the conformational changes that occur upon Cys binding to the ACT domain in AmiPatA using Circular Dichroism?CD?.Furthermore,the key residues involved in binding of Cys in the ACT domain of AmiPatA were investigated.