Sequence alignment of SUD between SARS-CoV (Genbank: AY291315) and SARS-CoV-2 (GenBank: MN908947). Domains Mac2 (SUD-N), Mac3 (SUD-M) and DPUP (SUD-C) range from K389 to L526, G527 to S652 and K653 to S720, respectively. The first 16 residues of Mac2 are boxed in blue. This figure was generated by using the ESPript server (http://espript.ibcp.fr/ESPript/ESPript/). 