The Mechanics of Genome Ejection in Bacterial Viruses

California Institute Of Technology, Pasadena CA

Investigators

Abstract

The goal of this work is to examine the mechanical processes that attend the packaging and ejection of genomic DNA in viruses. The research links theoretical models of the ejection process with single-molecule experiments aimed at testing the predictions of the theory. The theoretical models are based upon a treatment of the energetic cost to bend the DNA molecule in conjunction with the energy of interaction between the charges along the double-stranded DNA helix. Until now, these mechanical measurements have only been carried out in in vitro studies in which the viruses are taken out of their natural context. These earlier studies will be complemented by experiments aimed at watching individual infection events as viruses deliver their genomic DNA into bacteria. This work merges biological and mechanical perspectives to develop quantitative understanding of the life cycles of bacterial viruses. Further, this work should be seen as a specific case study in a broader analysis of the physical principles underlying how both viruses and cells manage their genomes. An extensive outreach effort carried out at Caltech and known as physical biology bootcamp will use the single-molecule experiments in intensive laboratory courses held every summer. These courses bring together professors, postdocs, grad students and undergrads in an informal but intense atmosphere over a ten-day period.