Some Close-Guarded Practices Of The XMU-MP-1 Revealed
These two positions are also part of a larger cluster of coevolving positions (122A, 174S, 186V, 202V, and 226L), all within the 50�C230 HA region, which demarcates the virus from its previous H7 ancestors (see the Experimental Procedures). The above observations indicate that the H7N9 HA has evolved to be distinct from its predecessors. Previous H7 strains carrying single mutations (from the coevolving cluster) are predominantly from the Eurasian lineage, suggesting that viruses from this lineage have higher potential to generate variants when compared to the American lineage (Figure?S3). Nucleotide analyses of the RBS-proximal region of HA (residues buy XMU-MP-1 50�C230 of HA1) of Eurasian sequences from 1902 to 2013 show strong diversifying (positive) selection ALPI at 156 (see the Experimental Procedures). The same position has been shown to be under selection pressure in the H1 subtype as well (Li et?al., 2011). Previously, we defined a quantitative metric to compare the antigenicity of two HAs. Briefly, the metric, called antigenic intactness (AI), is directly proportional to the fraction of residues conserved in the immunodominant antigenic sites between two HAs. In our previous work, we showed good agreement between AI values and antigenic relatedness metric computed from ferret antisera HA inhibition (HI) cross-reactivity data (Tharakaraman et?al., 2013), indicating that AI values could be applied to predict vaccine-induced cross-reactive antibody responses. Critically, strains that are antigenically related had AI > 80%, whereas strains JNJ-42756493 that are not related to each other had AI?