In Figure 4A, the structure of Rhinolophus ferrumequinum ACE2 in complex with Bt-CoV/Rp3/2004 S RBD is superimposed to ACE2 structures (residues 1–358) of domestic and wild animal species as derived from the last step of 1 ns molecular dynamics. The ACE2 structures are very similar (RMSD on backbone heavy atoms: 4.76 Å), suggesting that the BtCoV/Rp3/2004 S protein is potentially adapt to undertake efficacious interaction with ACE2 of domestic and wild animals. In Figure 4B multiple sequence alignments indicate that ACE2 residues involved in the interaction with BtCoV/Rp3/2004 S protein are conserved in all domestic and wild species except for Canis lupus familiaris and Vulpes vulpes.
Figure 4 (A) The structure of Rhinolophus ferrumequinum ACE2 in complex with Bt-CoV/Rp3/2004 S RBD is superimposed to ACE2 (residues 1–358) of domestic and wild animal species as derived from the last step of 1 ns molecular dynamics ribbon representation. (B) Residues of ACE2 (belonging to Italian domestic and wild animals) interacting with Bt-CoV/Rp3/2004 S RBD, compared to residues of hACE2 interacting with S protein RBD. Residues highlighted in blue are preserved; residues in green have similar chemical characteristics.