Fig. 4: Structural and functional analysis of key residues in the molecular interaction of eqACE2/PT-RBD and eqACE2/Omicron BA.1-RBD.
a SPR analysis of the binding affinity of wt/mutated RaTG13-RBD and SARS-COV-2 PT-RBD with human or eqACE2. bāe Structural details of site 494 of the RBD and involved residues of eqACE2/SARS-COV-2 PT-RBD (b), eqACE2/RaTG13-RBD (c), hACE2/RaTG13-RBD (d) and hACE2/SARS-COV-2 PT-RBD (e). RaTG13-RBD, SARS-COV-2 PT-RBD, eqACE2 and hACE2 are colored purple, orange, cyan, and wheat, respectively. f SPR analysis of the binding affinity of SARS-COV-2 PT-RBD, Omicron BA.1-RBD and mutated SARS-COV-2 PT-RBD. g The structural details of eqACE2/SARS-COV-2 PT-RBD (orange) and eqACE2/Omicron BA.1-RBD (green) around the sites referred above each picture. Residues involved in the interaction are represented as sticks. h The original conformation surrounding G496 of eqACE2/Omicron BA.1-RBD (left) and the modelled conformation of G496S (right) are shown. The modelled S496 is colored in white and the modelled H-bonds are represented by yellow dashes. The water molecule was represented as red sphere. The disks indicate pairwise overlap of atomic van der Waals radii between atoms. Small green disks and large red disks indicate slight and significant van der Waals overlap. Everything else lies between those extremes. i Structural comparison of Y501 and the involved residues of hACE2/Alpha-RBD (left) and modelled N501Y substitution of eqACE2/SARS-COV-2 PT-RBD. The water molecule is shown as red sphere and the modelled Y501 is colored in white. The Ļ-Ļ interaction, actual polar interaction and putative polar interaction for modelled Y501 are represented with blue, red and yellow dotted lines, respectively. The disks indicate pairwise overlap of atomic van der Waals radii between atoms. The dissociation constant (KD) of each binding test is calculated from 3 independent repeats and are presented as meanāĀ±āSD. Source data are provided as a Source Data file.
