SARS-CoV-2 spike protein receptor binding domain and N-terminal domain (Spike RBD and NTD)

The SARS-CoV-2 spike protein mediates viral entry into host cells. The S1 subunit contains two critical domains: - The receptor binding domain (RBD) directly binds the human ACE2 receptor to initiate infection[2][3][4][7]. Mutations in this domain can affect binding affinity, antibody escape, and transmissibility, and most neutralizing antibodies and vaccines target this region[6]. - The N-terminal domain (NTD) sits at the amino end of S1 and is highly glycosylated, functioning in viral immune evasion and as an alternative antibody target. Its biological role is less well-defined than the RBD, but it can modulate spike protein antigenicity and some antibodies neutralize the virus by binding the NTD[5]. Both RBD and NTD are structurally distinct and have been crystallized; drugs and vaccines targeting these domains aim to prevent viral entry, neutralize the virus, or monitor immune response after infection/vaccination[3][5][6]. Note: Drug development and structure-based classification typically treat the RBD and NTD as separate entities. Grouping them together as a single "target" is nonstandard and can hinder precise therapeutic or diagnostic mapping[3][4][5].

Other names

Spike RBDSpike NTDS1 receptor-binding domainS1 N-terminal domainSARS-2-S RBDSARS-CoV-2 S protein RBDSARS-CoV-2 spike glycoprotein RBD and NTD

Block RBD-ACE2 interaction to prevent viral entry[2][4][6][7] Neutralize virus by binding RBD or NTD, preventing attachment/fusion Stabilize spike protein in prefusion state to maximize immune recognition in vaccines[1][5]