Decomposition of the SARS-CoV-2-ACE2 interface reveals a common trend among emerging viral variants

New viral variants of the SARS-CoV-2 virus show enhanced infectivity compared to wild type, resulting in an altered pandemic situation in affected areas. These variants are the B.1.1.7 (United Kingdom), B.1.1.7 with the additional E484K mutation, the B.1.351 variant (South Africa) and the P.1 variant (Brazil). Understanding the binding modalities between these viral variants and the host cell receptor ACE2 allows depicting changes, but also common motifs of virus-host cell interaction. The trimeric spike protein expressed at the viral surface contains the receptor-binding domain (RBD) that forms the molecular interface with ACE2. All the above-mentioned variants carry between one and three amino acid exchanges within the interface-forming region of the RBD, thereby altering the binding interface with ACE2. Using molecular dynamics simulations and decomposition of the interaction energies between the RBD and ACE2, we identified phenylalanine 486, glutamine 498, threonine 500 and tyrosine 505 as important interface-forming residues across viral variants. We also suggest a reduced binding energy between RBD and ACE2 in viral variants with higher infectivity, attributed to residue-specific differences in electrostatic interaction energy. Importantly, individual amino acid exchanges not only influence the affected position, but also alter the conformation of surrounding residues and affect their interaction potential as well. We demonstrate how computational methods can help to identify changed as well as common motifs across viral variants. These identified motifs might play a crucial role, in the strategical development of therapeutic interventions against the fast mutating SARS-CoV-2 virus.