Structure of SARS Coronavirus Spike Receptor-Binding Domain Complexed with Receptor

TLDR

The SARS‑CoV spike protein binds to the cellular receptor ACE2 via a defined receptor‑binding domain (RBD). The study aims to use the RBD structure to design truncated, disulfide‑stabilized RBD variants for coronavirus vaccine development. The authors determined a 2.9‑Å crystal structure of the SARS‑CoV RBD in complex with the ACE2 peptidase domain. The crystal structure reveals a concave RBD surface that engages the N‑terminal lobe of ACE2 and highlights residue changes that enable efficient cross‑species infection and human‑to‑human transmission.

Abstract

The spike protein (S) of SARS coronavirus (SARS-CoV) attaches the virus to its cellular receptor, angiotensin-converting enzyme 2 (ACE2). A defined receptor-binding domain (RBD) on S mediates this interaction. The crystal structure at 2.9 angstrom resolution of the RBD bound with the peptidase domain of human ACE2 shows that the RBD presents a gently concave surface, which cradles the N-terminal lobe of the peptidase. The atomic details at the interface between the two proteins clarify the importance of residue changes that facilitate efficient cross-species infection and human-to-human transmission. The structure of the RBD suggests ways to make truncated disulfide-stabilized RBD variants for use in the design of coronavirus vaccines.