|Influenza A H5N1 (A/Egypt/N05056/2009) Hemagglutinin / HA Protein (His Tag)||HA|
|Influenza A H5N1 (A/Egypt/N05056/2009) Hemagglutinin Protein (HA1 Subunit) (His Tag)||HA|
In virus classification influenza viruses are RNA viruses that make up three of the five genera of the family Orthomyxoviridae: Influenza A, Influenza B and Influenza C, which are very similar in overall structure. The type A viruses are the most virulent human pathogens among the three influenza types and cause the most severe disease. The influenza A virus can be subdivided into different serotypes based on the antibody response to these viruses. The serotypes that have been confirmed in humans, ordered by the number of known human pandemic deaths. Hemagglutinin (HA) and neuraminidase (NA) are the two large glycoproteins on the outside of the viral particles. HA is a lectin that mediates binding of the virus to target cells and entry of the viral genome into the target cell, while NA is involved in the release of progeny virus from infected cells, by cleaving sugars that bind the mature viral particles. These different types of HA and NA form the basis of the H and N distinctions in. There are 16 H and 9 N subtypes known.