Figure 2.

The proposed dockable surface groove for FLCS_Spike in Furin, proximal to its catalytic triad. To demarcate the proposed binding pocket, a semi-opaque surface representation (colored according to atom types) is chosen over and above a backbone cartoon. The catalytic triad (D153, H194, S368) is presented as ‘balls and sticks’ and are labeled in ‘white’ over and above the cartoon display. Among all exposed and partially exposed anionic residues (see Table S3, Supplementary Materials), the ones that are in close vicinity to the dockable groove surface are also shown in ‘balls and sticks’ and are further labeled in ‘black’. These residues are amenable to form interfacial salt-bridges with the FLCS_Spike–arginines (in ₆₈₁PRRAR₆₈₅) and collectively add to the potential of forming dynamically interchangeable ionic bond networks at the Spike–Furin interface.