Figure 1.

Roles of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) structural proteins. The spike protein (S), which provides the crown shape, mediates the binding of the virus to the host’s angiotensin-converting enzyme 2 (ACE2) receptors and determines its affinity for the host. The nucleocapsid protein (N), which encloses the viral genome, is known to regulate transcription and immunoreaction. The membrane protein (M), which is the most common structural protein, seems to be involved in viral assembly and maturation. The envelope protein (E), which is the smallest structural protein, functions as an ion channel and assists in viral assembly and budding.