An Evolutionary Distinct Nipah Virus N-Glycosylation Site Provides Stability for Receptor Engagement

Nipah virus is a deadly paramyxovirus with 40-75% mortality and >750 cases since 1998. Currently there are no clinically approved vaccines or therapeutics to treat infection. Nipah is an enveloped virus with two surface glycoproteins, the trimeric fusion glycoprotein (F), and the tetrameric attachment glycoprotein (G), which is responsible for cellular attachment via binding to the host ephrin B2/B3 receptor. Glycosylation can substantially affect immunogenicity, receptor binding and structural conformations for virus glycoproteins, but its effects on Nipah G receptor engagement have not been studied. Here, phylogenetic and mass spectrometry analysis of the Nipah G Malaysia strain reveal how N-glycosylation has evolved since the appearance of the virus in 1998. We discovered that the N481 sequon is not conserved and the threonine/serine in the glycosylation site is critical for maintaining long-range stability of G subunits that facilitates ephrin B2 binding affinity. Together, these data reveal plasticity of N-glycosylation sites across Nipah species and the presence of hydrogen bonding networks that contribute to G stability and host engagement - results that are valuable for understanding virus attachment/entry mechanisms and the rationale design of structure-based vaccines.