Bat-derived influenza hemagglutinin H17 does not bind canonical avian or human receptors and most likely uses a unique entry mechanism.
Sun, X., Shi, Y., Lu, X., He, J., Gao, F., Yan, J., Qi, J., Gao, G.F.(2013) Cell Rep 3: 769-778
- PubMed: 23434510 
- DOI: https://doi.org/10.1016/j.celrep.2013.01.025
- Primary Citation of Related Structures:  
4H32 - PubMed Abstract: 
A new influenza-like virus genome (H17N10) was recently discovered in bats and offers a new perspective about the origin and evolution of influenza viruses. The viral envelope glycoprotein hemagglutinin (HA) is responsible for influenza virus receptor binding, fusion, and entry into the cell; therefore, the structure and function of HA H17 was characterized. The 2.70 Å resolution crystal structure revealed that H17 has a typical influenza A virus HA fold, but with some special features, including a distorted putative sialic acid (SA) binding site and low thermostability. No binding to either the canonical human α2,6 SA-linkage or avian α2,3 SA-linkage receptor was observed. Furthermore, H17 glycan binding was not detected using a chip covering more than 600 glycans. Our results demonstrate that H17 is unique among characterized HAs and that the bat-derived influenza virus may use a different entry mechanism compared to canonical influenza viruses.
Organizational Affiliation: 
CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.