Fig. 1
Schematic representation of the SARS-CoV-2 genome organization. The RNA genome is translated from two overlapping reading frames, ORF1a and ORF1b, to generate two different polyproteins, pp1a and pp1ab, the latter is generated following a programmed ribosomal frameshift that occurs within the overlap between ORF1a and ORF1b. The two polyproteins are cleaved by the virus-encoded proteases PLpro (NSP3) and 3CLpro (NSP5) into a total of 16 non-structural proteins (NSPs). The sites cleaved by the PLpro (marked with red arrows) and 3CLpro (marked with yellow arrows) are indicated. Downstream of the ORF1b, the RNA genome encodes 10 more proteins, which are translated from sub-genomic mRNAs, including the structural proteins (spike (S), envelope (E), membrane (M) and nucleocapsid (N)) and several accessory proteins. The conserved motif (WVPRA) is found within NSP2 of pp1a and is marked on the lower part of the figure. Created in BioRender. Kristensen, T. (2025) https://BioRender.com/s80a354.
