Clarifying real receptor binding site between coronavirus HCoV-HKU1 and 9-O-Ac-Sia based on molecular docking.

Abstract

HCoV-HKU1 is a [Formula: see text]-coronavirus with low pathogenicity, which usually leads to respiratory diseases. At present, a controversial issue is that whether the receptor binding site (RBS) of HCoV-HKU1 is located in the N-terminal domain (NTD) or the C-terminal domain (CTD) in the HCoV-HKU1 S protein. To address this issue, we used molecular docking technology to dock the NTD and CTD with 9-oxoacetylated sialic acid (9-O-Ac-Sia), respectively, with the results showing that the RBS of HCoV-HKU1 is located in the NTD (amino acid residues 80-95, 25-32). Our findings clarified the structural basis and molecular mechanism of the HCoV-HKU1 infection, providing important information for the development of therapeutic antibody drugs and the design of vaccines.