Tertiary structures of HA protein of A/H7N9/2013_China (A).

<p>Trace diagram of HA monomer, loci S183D V195G L235Q I335T N410T D455N and V541A are mutated loci and are marked by red space-filled atoms. Mutated loci are all located at the receptor-binding (RB) domain. (<b>B</b>): <b>The space-filled atom diagram of HA protein.</b> Red spots are mutated loci that are inside of the head of the protein. There is no change in the fusogenic stalk (<b>F</b>) and the esterase (<b>E</b>) domain.</p>