Structural basis for the recognition of Lewis antigens by genogroup I norovirus
Kubota, T., Kumagai, A., Ito, H., Furukawa, S., Someya, Y., Takeda, N., Ishii, K., Wakita, T., Narimatsu, H., Shirato, H.(2012) J Virol 86: 11138-11150
- PubMed: 22855491 
- DOI: https://doi.org/10.1128/JVI.00278-12
- Primary Citation of Related Structures:  
3ASP, 3ASQ, 3ASR, 3ASS, 3AST - PubMed Abstract: 
Noroviruses (NoVs) bind to histo-blood group antigens, namely, ABH antigens and Lewis antigens. We previously showed the NoVs GI/2, GI/3, GI/4, and GI/8 were able to strongly bind to Lewis a (Le(a)) antigen, which is expressed by individuals who are nonsecretors. In this study, to investigate how Lewis antigens interact with GI NoV virion protein 1 (VP1), we determined the crystal structures of the P domain of the VP1 protein from the Funabashi 258 (FUV258) strain (GI/2) in complexes with Le(a), Le(b), H type 1, or A type 1 antigens. The structures were compared with those of the NV/68 strain (GI/1), which does not bind to the Le(a) antigen. The four loop structures, loop P, loop S, loop A, and loop B, continuously deviated by more than 2 Å in length between the Cα atoms of the corresponding residues of the FUV258 and NV/68 P domains. The most pronounced differences between the two VP1 proteins were observed in the structures of loop P. In the FUV258 P domain, loop P protruded toward the next protomer, forming a Le(a) antigen-binding site. The Gln389 residue make a significant contribution to the binding of the Le(a) antigen through the stabilization of loop P as well as through direct interactions with the α4-fucosyl residue (α4Fuc) of the Le(a) antigen. Mutation of the Gln389 residue dramatically affected the degree of binding of the Lewis antigens. Collectively, these results suggest that loop P and the amino acid residue at position 389 affect Lewis antigen binding.
Organizational Affiliation: 
Research Center for Medical Glycoscience, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan.