SARS-CoV-2 Ligands Database

The N-terminal Domain (NTD) is located at the beginning (N-terminus) of the S1 subunit of the spike protein. It plays a role in receptor recognition and binding, and it can interact with host cell surface molecules. The NTD is also a target for neutralizing antibodies, making it significant in vaccine development.

The Receptor-Binding Domain (RBD) is a critical region within the S1 subunit that directly interacts with the host cell receptor, specifically the ACE2 receptor in the case of SARS-CoV-2. The RBD undergoes conformational changes upon receptor binding, which is essential for the subsequent fusion of the viral and host membranes.

C-terminal Domain 1 (CTD1) is part of the S1 subunit and is located adjacent to the RBD. It may have roles in stabilizing the spike protein and facilitating interactions with other proteins. CTD1 can influence the conformation of the RBD and its accessibility to the ACE2 receptor.

C-terminal Domain 2 (CTD2) is another domain located in the S2 subunit of the spike protein. It is involved in the structural rearrangements that occur during the fusion process. CTD2 plays a role in stabilizing the post-fusion conformation of the spike protein, which is essential for the fusion of the viral membrane with the host cell membrane.