Vulnerabilities in coronavirus glycan shields despite extensive glycosylation

Yasunori Watanabe; Zachary T. Berndsen; Jayna Raghwani; Gemma E. Seabright; Joel D. Allen; Jason S. McLellan; Ian A. Wilson; Thomas A. Bowden; Andrew B. Ward; Max Crispin

We hypothesized that solvent-accessible, amino-acid residues on S proteins would be undergoing higher rates of mutations compared to buried residues and regions that are occluded by glycans, which are unable to be targeted by host immune responses. To that end, we performed an evaluation of amino-acid diversification on a residue-specific level, using publicly available gene sequences of SARS and MERS S. Firstly, we found that amino-acid diversity was elevated at known epitopes targeted by neutralizing antibodies, such as the N-. CC-BY 4.0 International license author/funder. It is made available under a The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.02.20.957472 doi: bioRxiv preprint terminal domain and the receptor binding domains, and reduced in the regions in the S2 domain, such as the fusion peptide, heptad repeat one, and the central helix domains, which are likely subject to greater functional constraints (Fig. 4A) .