Comparing types and sites of lysine acetylation on two aspartate aminotransferase domains
By: Maricarmen Gonzalez Torres and Naoki Kakehashi
Department: Biochemistry
Faculty Advisor: Dr. Misty L. Kuhn
Proteins in E. coli are acetylated both non-enzymatically and enzymatically via acetyl phosphate (AcP) and lysine acetyltransferases (KATs), respectively. A prior study showed over 600 E. coli proteins are post-translationally acetylated. While the locations via primary sequence are known, a 3D structural analysis has not been performed and not every protein has a crystal structure. Since advancements with artificial intelligence have enabled any protein sequence to be modeled into a 3D structure, we used AlphaFold models of the E. coli proteins that were identified as acetylated for our analysis. Next, we separated these proteins based on their structural topologies and used Pymol to visualize the models, highlight sites of acetylation, and color the domain boundaries. Our group selected proteins with aspartate aminotransferase topologies for further analysis. Aspartate aminotransferases are transaminase enzymes that catalyze the conversion of aspartate and alpha-ketoglutarate to oxaloacetate and glutamate. Their structures are separated into two different domains (Domain 1 and 2). We found acetylation occurred more frequently on Domain 2 than Domain 1, and noticed that there were more chemically acetylated proteins than enzymatically acetylated proteins. Our next step will be to determine if there are any correlations in the locations of acetylated lysine residues and functionalities of the various proteins that are acetylated.