Fig. 1.

The SARS-CoV-2 genome. The 30 kb genome of 2019-nCOV is a single-stranded positive-strand RNA (+ssRNA). Only one-third of the genome serves as a template for four structural proteins that are functionally involved in the infection process. The four structural proteins include the membrane (M), spike (S), envelope (E), and nucleocapsid (N); all accessory proteins are derived from sgRNA and are critical for infection.

2019-nCOV = 2019 novel coronavirus; SARS-CoV-2 = severe acute respiratory syndrome coronavirus 2; sgRNA = subgenomic RNA.