I study life at its borders. At the edge of our definition of life lies viruses, obligate parasites that invade cellular organisms to replicate. When a virus encounters a cell, it must recognize that cell through biomolecular interactions and then commandeer the cell to create copiesof the virus?s proteins. Research in my laboratory focuses on those biomolecular interactions between the virus and the cell to gain insight into viral mechanisms of invasion. I employ techniques in structural biology to peer at these interactions at the atomic scale and methods in cellular biochemistry to take these interactions apart and put them back together. Beyond viruses, I am also interested in the origins of life on Earth. How did cellular life arise from atoms and molecules on the surface of a young Earth over 3.5 billion years ago? All macromolecules are assembled from building blocks by existing macromolecules (enzymes). Could chains of macromolecules that carry genetic! informat ion be formed without an existing enzyme? If so, what chemical conditions and surfaces are necessary to bring together life?s building blocks and catalyze their linkage? Could the first cells resemble viruses? Answering these questions might help reveal how the last universal common ancestor of all living organisms arose.