Avian-to-Human Receptor-Binding Adaptation of Avian H7N9 Influenza Virus Hemagglutinin.
Xu, Y., Peng, R., Zhang, W., Qi, J., Song, H., Liu, S., Wang, H., Wang, M., Xiao, H., Fu, L., Fan, Z., Bi, Y., Yan, J., Shi, Y., Gao, G.F.(2019) Cell Rep 29: 2217
- PubMed: 31747596 
- DOI: https://doi.org/10.1016/j.celrep.2019.10.047
- Primary Citation of Related Structures:  
6ICW, 6ICX, 6ICY, 6ID2, 6ID3, 6ID5, 6ID8, 6ID9, 6IDA, 6IDB, 6IDD, 6IDZ - PubMed Abstract: 
Since 2013, H7N9 avian influenza viruses (AIVs) have caused more than 1,600 human infections, posing a threat to public health. An emerging concern is whether H7N9 AIVs will cause pandemics among humans. Molecular analysis of hemagglutinin (HA), which is a critical determinant of interspecies transmission, shows that the current H7N9 AIVs are still dual-receptor tropic, indicating limited human-to-human transmission potency. Mutagenesis and structural studies reveal that a G186V substitution is sufficient for H7N9 AIVs to acquire human receptor-binding capacity, and a Q226L substitution would favor binding to both avian and human receptors only when paired with A138/V186/P221 hydrophobic residues. These data suggest a different evolutionary route of H7N9 viruses compared to other AIV-subtype HAs.
Organizational Affiliation: 
School of Life Sciences, University of Science and Technology of China, Hefei 230026, China; CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing 100101, China.