Influenza A H4N4 (A/mallard duck/Alberta/299/1977) Hemagglutinin Protein (HA1 Subunit) (His Tag)

A DNA sequence encoding the N-terminal segment (Met 1-Arg 343) of the influenza hemagglutinin ((A/mallardduck/Alberta/299/1977 (H4N4)) (Q0A4G1), termed as HA1, was fused with a polyhistidine tag at the C-terminus.