The laboratory of John Gross investigates the control of eukaryotic gene expression at the level of mRNA metabolism. Half the lab studies the control of mRNA stability by the decapping enzyme (Dcp2) and its cofactors. The other half of the group investigates host nucleic acid immune systems that destroy or hypermutate foreign viral nucleic acid intermediates that form during replication. As part of the HARC center we are examining complexes between HIV and host proteins with the long-term goal of obtaining structural and mechanistic data that will pave the way for future therapeutics. We use structural data provided by NMR spectroscopy or X-ray crystallography to guide biophysical, biochemical, and genetic experiments with the ultimate goal of understanding molecular mechanisms at the cellular level.