Noroviral P particle: Structure, function and applications in virus-host interaction

Noroviruses are an important cause of epidemic acute gastroenteritis and the viruses recognize human histoblood group antigens (HBGAs) as receptors. The protruding (P) domain of noroviral capsid, the receptor-binding domain, forms subviral particles in vitro that retain the receptor-binding function. In this study we characterized the structure and HBGA-binding function of the P particle. Structure reconstruction using cryo-EM showed that the P particles are comprised of 12 P dimers that are organized in octahedral symmetry. The dimeric packing of the proteins in the P particles is similar to that in the norovirus capsid, in which the P2 subdomain with the receptor-binding interface is located at the outermost surface of the P particle. The P particles are immunogenic and reveal similar antigenic and HBGA-binding profiles with their parental virus-like particle, further confirming the shared Surface structures between the two types of particles. The P particles are easily produced in E. coli and yeast and are stable, which are potentially useful for a broad application including vaccine development against noroviruses. (C) 2008 Elsevier Inc. All rights reserved.