About the Lab

Structural Studies on Animal Viruses

Research in the Prasad Laboratory is focused on determining structure-function relationships in medically important viruses that are pathogens to humans and other animals. The current focus is on viruses that are causative agents of endemic severe diarrhea in humans. These viruses include rotavirus, calicivirus, and Norwalk virus. Rotavirus is the major pathogen of infantile gastroenteritis. More than a million children die every year worldwide because of rotaviral gastroenteritis. Recently, several other viruses, including calicivirus and Norwalk virus, also have been shown to be causative agents of pediatric diarrhea.

Our three-dimensional structural analyses have provided architectural descriptions of these viruses. Our studies using monoclonal antibodies, reassortants, and baculovirus-expressed virus-like particles have provided insights into the molecular mechanisms of cell entry, infectivity, transcription, and assembly of rotavirus. Rotavirus is a member of the virus family Reoviridae. Comparative structural analysis of other members in this family, such as blue-tongue virus and aquareovirus, is being carried out to provide a unified picture of the molecular mechanisms underlying the morphogenesis and pathogenesis of these large, complex, multi-layered viruses.

We perform our three-dimensional structural analyses by using electron cryomicroscopy and computer image-processing techniques. In favorable circumstances, x-ray crystallography is being used to study either entire virus particles or their protein components. We have recently determined the structure of Norwalk virus capsids to atomic resolution by using x-ray crystallographic techniques.