Fig. 1: The crystal structure of ligand free Mpro is amenable to X-ray fragment screening.
From: Crystallographic and electrophilic fragment screening of the SARS-CoV-2 main protease
a Cartoon representation of the Mpro dimer. The nearmost monomer is shown with secondary structure features coloured to demarcate domains I, II, and III, in orange, cyan, and violet respectively. The active site of the rear monomer is indicated by the presence of a peptide-based inhibitor in green, generated by aligning the ligand-free structure with pdb 6Y2F [10.2210/pdb6y2f/pdb]. A yellow sphere indicates Ser1 from the dimer partner that completes the active site. b Residues of the active site are labelled, and subsites involved in ligand binding are shown with circles. c Active site plasticity is observed when comparing the apo structure to peptide inhibitor bound structures (green—Apo, grey—6Y2F [10.2210/pdb6y2f/pdb], pink 6LU7 [10.2210/pdb6lu7/pdb]). Displacement distances associated with loop movements are indicated.
