Structural basis for the divergent evolution of influenza B virus hemagglutinin.
Ni, F., Kondrashkina, E., Wang, Q.(2013) Virology 446: 112-122
- PubMed: 24074573 
- DOI: https://doi.org/10.1016/j.virol.2013.07.035
- Primary Citation of Related Structures:  
4M40, 4M44 - PubMed Abstract: 
Influenza A and B viruses are responsible for the severe morbidity and mortality worldwide in annual influenza epidemics. Currently circulating influenza B virus belongs to the B/Victoria or B/Yamagata lineage that was diverged from each other about 30-40 years ago. However, a mechanistic understanding of their divergent evolution is still lacking. Here we report the crystal structures of influenza B/Yamanashi/166/1998 hemagglutinin (HA) belonging to B/Yamagata lineage and its complex with the avian-like receptor analogue. Comparison of these structures with those of undiverged and diverged influenza B virus HAs, in conjunction with sequence analysis, reveals the molecular basis for the divergent evolution of influenza B virus HAs. Furthermore, HAs of diverged influenza B virus strains display much stronger molecular interactions with terminal sialic acid of bound receptors, which may allow for a different tissue tropism for current influenza B viruses, for which further investigation is required.
Organizational Affiliation: 
Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Department of Bioengineering, Rice University, Houston, TX 77005, USA.