has part has part has_part is characteristic AA variant of has mutated from has amino acid position asparagine lysine SARS-CoV-2 Omicron variant N440K in SARS-CoV-2 S protein 440 Anthony Huffman An AA mutation or AA variant that has mutated an amino acid at position 211 into a lysine in S protein. https://cov-lineages.org/ AA variant in SARS-CoV-2 S protein RBM region