Figure 1. . SARS-CoV-2 genome consists of a positive 5’-capped and 3’-polyadenylated ssRNA.

The viral genome sequence is approximately 30,000 bases in length. OFR1a and OFR1b genes are located on the 5’-end and codify two long polypeptides, defined as pp1a and pp1ab, respectively. These polypeptides are cleaved into 16 Nsps (not shown), from Nsps 1 to Nsps 16, such as some transmembrane domains, including Nsp4 and Nsp6 (see text) as well as Nsp12 Pol/RdRp. This enzyme is needed for efficient replication and transcription of the viral RNA genome. Furthermore, SARS-CoV-2 genome on 3’-terminus encodes four structural proteins, the nucleocapsid (N) protein, the matrix (M) protein, the small envelope (E) protein and the spike (S) glycoprotein and also some accessory proteins, like ORF 3a, 3 b, 6, 7a, 7b, 8, 9b, 10 and 14.

Nsp: Nonstructural protein; OFR: Open-reading frame; Pol/RdRp: RNA-dependent RNA polymerase.