Skip to main content
. 2023 Jul 21;15(7):1600. doi: 10.3390/v15071600

Figure 1.

Figure 1

SUMOylation of SARS-CoV-2 N protein. (A) Diagram of the fluorescence fusion protein CyPet-SUMO1 and YPet-N for the qFRET-based SUMOylation assay. (B) In vitro SUMOylation assay with the FRET as a reporter signal. The fusion protein CyPet-SUMO is first bound to E1 activating enzyme, for the intermediate E1-Cypet-SUMO1 thioester bond at Cys173 to Gly98 on SUMO1. The SUMO is then transferred to the catalytic Cys-93 of E2 conjugating enzyme. The E3 ligase and target protein are said to non-covalently interact with the E2-SUMO1 complex. The CyPet-SUMO1 is then shuttled to a lysine on the target protein, to be covalently bound by an isopeptide bond. (C) The Western-blot of SUMOylated N protein in the in vitro reaction containing E1, E2 and E3 using a monoclonal anti-SUMO1 antibody.