Severe acute respiratory syndrome coronavirus 2 Omicron BA.2 variant spike protein receptor-binding domain (SARS-CoV-2 Omicron BA.2 RBD)

The SARS-CoV-2 Omicron BA.2 spike protein receptor-binding domain (RBD) is a critical component of the viral spike (S) glycoprotein responsible for mediating infection (PubMed: 35418631). It specifically binds to the human angiotensin-converting enzyme 2 (ACE2) receptor on the surface of host cells, initiating the process of viral entry and membrane fusion (UniProt: P0DTC2). The BA.2 subvariant of Omicron contains a unique set of mutations within the RBD, such as T376A, D405N, and R408S, which distinguish it from the earlier BA.1 lineage (Nature: 10.1038/s41586-022-04730-w). These mutations contribute to increased transmissibility and significant evasion of neutralizing antibodies elicited by prior infection or vaccination (Science: 10.1126/science.abn7760). Consequently, the BA.2 RBD is a primary target for the development of next-generation vaccines and therapeutic monoclonal antibodies. While many early-pandemic antibodies lost potency against this variant, drugs like bebtelovimab were developed to maintain high-affinity binding to conserved epitopes within the RBD (FDA: Bebtelovimab Fact Sheet). Understanding the structural dynamics of the BA.2 RBD is essential for monitoring the evolution of the virus and ensuring the continued efficacy of COVID-19 countermeasures (PubMed: 35397611).

Other names

BA.2 RBDOmicron BA.2 spike RBDSARS-CoV-2 B.1.1.529.2 receptor-binding domainSpike protein RBD (Omicron BA.2)SARS-CoV-2 Omicron BA.2 S-RBD

Monoclonal antibodies and vaccine-induced antibodies bind to the receptor-binding domain (RBD) to sterically hinder its interaction with the human angiotensin-converting enzyme 2 (ACE2) receptor, thereby preventing viral entry into host cells (PubMed: 35397611).