Mutations in B.1.617.2 variant
The spike protein of B.1.617.2 variant contains nine mutations in the S1 subunit and one mutation in the S2 subunit. In the S1 subunit, five mutations are present in the N-terminal domain containing binding sites (epitopes) for neutralizing antibodies. In addition, two mutations are present in the receptor-binding domain of the S1 subunit, which is known to influence antibody-mediated neutralization and infectivity. Among the three remaining mutations, two are known to increase angiotensin-converting enzyme 2 (ACE2) binding, viral replication, and spike protein cleavage at the S1/S2 site