Cell, 24 January, 2022, DOI：https://doi.org/10.1016/j.cell.2022.01.019

Structural and functional characterizations of infectivity and immune evasion of SARS-CoV-2 Omicron

Zhen Cui, Pan Liu, Nan Wang, Lei Wang, Kaiyue Fan, Qianhui Zhu, Kang Wang, Ruihong Chen, Rui Feng, Zijing Jia, Minnan Yang, Ge Xu, Boling Zhu, Wangjun Fu, Tianming Chu, Leilei Feng, Yide Wang, Xinran Pei, Peng Yang, Xiaoliang Sunney Xie, Lei Cao, Yunlong Cao, Xiangxi Wang

Abstract

The SARS-CoV-2 Omicron variant with increased fitness is spreading rapidly worldwide. Analysis of cryo-EM structures of the spike (S) from Omicron reveals amino acid substitutions forging interactions that stably maintain an active conformation for receptor recognition. The relatively more compact domain organization confers improved stability and enhances attachment but compromises the efficiency of the viral fusion step. Alterations in local conformation, charge, and hydrophobic microenvironments underpin the modulation of the epitopes such that they are not recognized by most NTD- and RBD-antibodies, facilitating viral immune escape. Structure of the Omicron S bound with human ACE2, together with the analysis of sequence conservation in ACE2 binding region of 25 sarbecovirus members, as well as heatmaps of the immunogenic sites and their corresponding mutational frequencies, sheds light on conserved and structurally restrained regions that can be used for the development of broad-spectrum vaccines and therapeutics.

Article link：https://www.cell.com/cell/fulltext/S0092-8674(22)00077-0