(a) Overall superposition of the Cα traces from the SARS-CoV Mpro monomer present in our asymmetric unit (coloured red, PDB code 2c3s
) with the active monomer A of Yang et al. (2003) (shown in blue, PDB code 1uj1
, chain A). A residual rotation of 4.5° is needed to then bring the two equivalent monomers B into coincidence. The active-site residues of each monomer are represented as sticks. (b) Detailed view of the active site represented as green sticks (2c3s
, this work) superimposed onto the active monomer A of SARS-CoV Mpro (1uj1
, chain A). The putative hydrogen bonds (dashed lines) formed by the spatially conserved water molecule (red sphere) are shown.