This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
Intellectual Merit: Aminoglycosides are a large group of antibiotics produced by actinomycetes as a defensive measure against other bacteria. To avoid effects of these antibiotics, they also produce enzymes that modify aminoglycosides (AGMEs) and render them harmless. A large majority of these enzymes (more than fifty known today) are capable of modifying a number of aminoglycosides; conversely a single aminoglycoside can be modified by a large number of enzymes. Such intertwined interactions between these molecules render the structural and functional studies quite challenging. This project is designed to dissect dynamic, thermodynamic, and structural properties of various enzyme aminoglycoside complexes using three enzymes, as representatives of each of the three catalytic categories, with the ultimate goal of understanding the molecular properties of these promiscuous enzymes as a whole group. This project also involves efforts to bridge computational and experimental aspects of a biologically significant and challenging problem. Identification of sites on ligands and proteins that are affected by the global properties of the enzyme versus those affected only by sub-global and local structural perturbations may yield valuable clues to understand promiscuity of these enzymes. Common properties of complexes of three different enzymes with similar ligands should yield important leads towards understanding of molecular determinants of enzyme-ligand interactions by AGMEs as a group. Combined use of experimental and computational data will lead to design new strategies to expand horizon of both approaches as applied to enzyme ligand complexes in general.
Broader Impact: This project involves interdisciplinary and international collaboration, which will provide training opportunities for experimentalists in computational aspects of ligand-protein interactions. This project will also provide hands on training opportunities through several programs that include Biochemistry Cellular and Molecular Biology graduate program, NSF-funded, Scalable Computing and Leading Edge Innovative Technologies (SCALE-IT) and National Institute for Mathematical and Biological Synthesis (NIMBioS), NIH-funded, Program for Excellence and Equity in Research (PEER) (Minority directed), and Genome Science Technology Program (jointly between the University of Tennessee and Oak Ridge National Laboratories) for graduate student and postdoctoral scientist training; Biological Sciences and Chemistry majors, Chancellor's Scholars, and McNair Scholars (for undergraduates from predominantly minority schools) for undergraduate training; and Pre-Collegiate Research Scholar Program, Math and Science Center (directed to students mostly from rural areas of Tennessee), and Tennessee Junior Science and Humanities Symposium for training of high school students at the University of Tennessee Knoxville. In addition, this project will help in raising the scientific literacy of public in quantitative and molecular aspects of biological sciences by outreach activities through several programs at UTK including Research Experience for Preservice Teachers, Academic Outreach, and Science Technology Engineering and Mathematics (STEM) Programs.
