My lab examines structure-function relationships in a variety of macromolecular systems, using computer-based modeling and simulations, supported by experiments done in my collaborators' labs.

Over the years, I have worked on a variety of problems, primarily involving nucleic acids, and protein-nucleic acid complexes, especially the ribosome and viruses. The other pages of this website provide more information.

Since moving to Penn in 2015, my research has been primarily aimed at determining the mechanism by which double-stranded DNA (dsDNA) viruses use the energy of ATP hydrolysis to drive the DNA into the pre-formed capsid. This work is based on the scrunchworm hypothesis, in which I argued that DNA is not just a passive substrate of the motor but is, instead, the active force-generating component. Our recent work, combining molecular dynamics simulations and theoretical analyses, supports the scrunchworm model; it also suggests that electrostatic forces produce the conformational changes in the DNA that are responsible for force generation and DNA translocation. Our latest publication on this work is found here.

For more information on this work, click here.