Overview:

The receptor binding domain (RBD) of the SARS-CoV-2 spike glycoprotein that recognizes the host ACE2 receptor is a major determinant of viral entry and neutralization, and is also the most divergent region (1). N439K variant of SARS-CoV-2 spike protein has been reported in 34 countries since January 2021. N439K Spike protein has enhanced binding affinity to the hACE2 receptor through formation of new salt bridges, however there is no evidence for change in disease severity compared to wild type (2). Hence, as the new variants displace the first-wave virus, it is pivotal to evaluate their transmissibility, virulence and their possible tendency to escape antibody neutralization (3).

Gene Aliases:

2019-nCoV RBD, SARS-CoV-2 spike RBD, novel coronavirus spike RBD, nCov spike RBD.

Genbank Number:

MN908947

References:

1. Lan J, et al: Crystal structure of the 2019-nCov spike receptor-binding domain bound with the ACE2 receptor. bioRxiv. doi: https://doi.org/10.1101/2020.02.19.956235

2. Thomson EC, et al: Circulating SARS-CoV-2 spike N439K variants maintains fitness while evading antibody-mediated immunity. Cell. 2021, ISSN 0092-8674. doi: 10.1016/j.cell.2021.01.037.

3. Starr TN, et al: Molecular dynamic simulation reveals E484K mutation enhances spike RBD-ACE2 affinity and the combination of E484K, K417N and N501Y mutations (501Y.V2 variant) induces conformational change greater than N501Y mutant alone, potentially resulting in an escape mutant. Cell. 2020, 182(5):1295-1310.