Viruses, Vol. 13, Pages 2162: Structural Studies on the Shapeshifting Murine Norovirus

Viruses, Vol. 13, Pages 2162: Structural Studies on the Shapeshifting Murine Norovirus Viruses doi: 10.3390/v13112162 Authors: Michael B. Sherman Alexis N. Williams Hong Q. Smith B. Montgomery Pettitt Christiane E. Wobus Thomas J. Smith Noroviruses are responsible for almost a fifth of all cases of gastroenteritis worldwide. The calicivirus capsid is composed of 180 copies of VP1 with a molecular weight of ~58 kDa. This coat protein is divided into the N-terminus (N), the shell (S) and C-terminal protruding (P) domains. The S domain forms a shell around the viral RNA genome, while the P domains dimerize to form protrusions on the capsid surface. The P domain is subdivided into P1 and P2 subdomains, with the latter containing the binding sites for cellular receptors and neutralizing antibodies. Reviewed here are studies on murine norovirus (MNV) showing that the capsid responds to several physiologically relevant cues; bile, pH, Mg2+, and Ca2+. In the initial site of infection, the intestinal tract, high bile and metal concentrations and low pH cause two significant conformational changes: (1) the P domain contracts onto the shell domain and (2) several conformational changes within the P domain lead to enhanced receptor binding while blocking antibody neutralization. In contrast, the pH is neutral, and the concentrations of bile and metals are low in the serum. Under these conditions, the loops at the tip of the P domain are in the open conformation with the...
Source: Viruses - Category: Virology Authors: Tags: Review Source Type: research