Posted on

SARS-CoV-2 Receptor Binding Domain Delta Plus Mutant 6VXX

featured image

The SARS-CoV2 Delta Plus variant was first reported in India. This new variant, was shown to carry mutation K417N on its receptor-binding domain (RBD), a mutation previously reported in the Beta variant. Experts believe it contributes to immune evasion in SARS-CoV-2 and synergistic with mutation L452R, another mutation known to also contribute to immune evasion. In contrast, T478K is located between the RBD and the ACE2 receptor. Reports indicate that the global prevalence of this amino acid change increases transmissibility.

The SARS-CoV-2 Spike Glycoprotein is a key target for vaccines, therapeutic antibodies, and diagnostics. Biologic Models designed this 3D printed protein model of the SARS-CoV-2 Receptor Binding Domain Delta Plus Mutant 6VXX helps research scientists track viral mutations.

SARS-CoV-2 Receptor Binding Domain Delta Plus Mutant 6VXX

The Receptor Binding Domain of the SARS-CoV-2 Spike Glycoprotein (PDB ID: 6VXX seen below) is the apex of the Spike that reaches out and binds ACE2 Receptors. It is characterized by a Binding motif (dark green) that localizes most of the SARS-CoV-2 residues that interact with ACE2 residues.  Targeting these residues with Neutralizing Antibodies is a proven strategy to inhibit viral infection. Furthermore, mutations to these residues may dramatically change how the virus interacts with ACE2 or worse, evade immune responses. Mutations to these residues may also significantly impact both immune evasion, and transability.


Shown here are 4 mutations described by

  • K417N denotes the “Delta Plus” variant.
  • L452R. The substitution at position 452, a leucine-to-arginine substitution, confers stronger affinity of the spike protein for the ACE2 receptor[44] and decreased recognition capability of the immune system.[8][45]
  • T478K.[9][29] The exchange at position 478 is a threonine-to-lysine substitution.[43]

Biologic Explorer: 6VXX-RBD Delta Plus Mutant

Below is the x-ray crystallography data for the Delta Plus mutant. Colored green is the Receptor Binding Domain (RBD), dark green the RBD Binding Motif, and then purple is Arginine of the L452R mutation,  light blue is Lysine of the T478K mutation, and orange the Asparagine of the K417N mutation.


3D Print SARS-CoV-2 Receptor Binding Domain Delta Plus Mutant 6VXX