A highly conserved cryptic epitope in the receptor binding domains of SARS-CoV-2 and SARS-CoV

Abstract

Targeting the SARS-CoV-2 spike The surface of severe acute respiratory syndrome–coronavirus 2 (SARS-CoV-2) is decorated with trimeric spikes that bind to host cell receptors. These spikes also elicit an antibody response, so understanding antibody recognition may aid in vaccine design. Yuan et al. determined the structure of CR3022, a neutralizing antibody obtained from a convalescent SARS-CoV–infected patient, in complex with the receptor-binding domain of the SARS-CoV-2 spike. The antibody binds to an epitope conserved between SARS-CoV-2 and SARS-CoV that is distinct from the receptor-binding site. CR3022 likely binds more tightly to SARS-CoV because its epitope contains a glycan not present in SARS-CoV-2. Structural modeling showed that the epitope is only revealed when at least two of the three spike proteins are in a conformation competent to bind the receptor. Science , this issue p. 630