Analysis of Adaptation Mutants in the Hemagglutinin of the Influenza A(H1N1)pdm09 Virus
Figure 4
Effect of D222E in receptor binding.
A, wild-type HA; B, D222E mutant. Protein is shown as green ribbons. Amino acids surrounding position 222 are illustrated as sticks; receptor and carbohydrate residues are depicted as magenta sticks. In the wild-type HA, D222 forms a triad with K219 and E224 that interact with galactose from the human receptor. In D222E, only K219 and E224 interact with galactose, while E222 interacts through water-mediated hydrogen bonds with nearby glycosylations originating at N87.