Cryo-EM analysis of a feline coronavirus spike protein reveals a unique structure and camouflaging glycans
Journal
Proceedings of the National Academy of Sciences of the United States of America
Journal Volume
117
Journal Issue
3
Pages
1438-1446
Date Issued
2020
Author(s)
Yang, T.-J.
Ko, T.-P.
Draczkowski, P.
Chien, Y.-C.
Chang, Y.-C.
Wu, K.-P.
Khoo, K.-H.
Danny Hsu, S.-T.
Abstract
Feline infectious peritonitis virus (FIPV) is an alphacoronavirus that causes a nearly 100% mortality rate without effective treatment. Here we report a 3.3-? cryoelectron microscopy (cryo-EM) structure of the serotype I FIPV spike (S) protein, which is responsible for host recognition and viral entry. Mass spectrometry provided site-specific compositions of densely distributed high-mannose and complex-type N-glycans that account for 1/4 of the total molecular mass; most of the N-glycans could be visualized by cryo-EM. Specifically, the N-glycans that wedge between 2 galectin-like domains within the S1 subunit of FIPV S protein result in a unique propeller-like conformation, underscoring the importance of glycosylation in maintaining protein structures. The cleavage site within the S2 subunit responsible for activation also showed distinct structural features and glycosylation. These structural insights provide a blueprint for a bettermolecular understanding of the pathogenesis of FIP. ? 2020 National Academy of Sciences. All rights reserved.
Subjects
Alphacoronavirus; Cryoelectron microscopy; Feline infectious peritonitis virus; Mass spectrometry; Protein glycosylation
SDGs
Other Subjects
glycan; virus spike protein; coronavirus spike glycoprotein; galectin; mannose; animal experiment; Article; binding site; conformation; controlled study; cryoelectron microscopy; Feline infectious peritonitis virus; glycosylation; host interaction; human; human cell; mass spectrometry; mouse; nonhuman; pathogenesis; priority journal; protein analysis; protein cleavage; protein structure; virus entry; virus strain; chemistry; cryoelectron microscopy; Feline coronavirus; HEK293 cell line; protein conformation; Coronavirus, Feline; Cryoelectron Microscopy; Galectins; Glycosylation; HEK293 Cells; Humans; Mannose; Protein Conformation; Spike Glycoprotein, Coronavirus
Type
journal article