We are undertaking a new initiative to examine how DNA is released from the icosahedral capsid to initiate an infection. DNA release or uncoating is being studied beginning with purified DNA-containing capsids and an in vitro uncoating system recently developed in our laboratory. Experiments are carried out to identify the DNA end that emerges first from the capsid and to clarify the nature of heterogeneity observed in the population of DNA-containing capsids. In vitro studies are being complemented with an analysis of DNA uncoating as it occurs in infected cells. This project focuses on identifying protein contacts between the capsid and the nuclear pore, the organelle through which DNA enters the host cell nucleus.
We are also continuing earlier studies that make use of a cell-free capsid assembly system to examine the way the portal becomes incorporated into the nascent capsid. We are testing the idea that assemlby involves a filamentous aggregate of the scaffolding protein bound to the portal and major capsid proteins. This is proposed to condense in a stepwise fashion to create the procapsid. Finally, in vitro studies are being performed to identify how components of the DNA packaging machinery are assembled on the capsid surface prior to their functoning in DNA translocation.
PhD - Harvard University
Structure and Assembly of the Herpes Simplex Virus Capsid