What is the protein coating in influenza virus A and B?

The influenza virus has a nucleic core with genetic material surrounded by a membrane bound protein coat consisting of four proteins: Hemagglutinin protein (H protein): the viral protein that enables it to attach to a host cell. Neuraminidase (N protein): an enzyme that cleaves sialic acid residues on hemagglutinin.

What is HA and NA in influenza?

The two glycoproteins of the influenza virus membrane, hemagglutinin (HA)3 and neuraminidase (NA), both recognize sialic acid (1,–3). Initiation of virus infection involves multiple HAs binding to sialic acids on carbohydrate side chains of cell-surface glycoproteins and glycolipids (4,–6).

How many proteins does influenza A have?

All rights reserved. With the HA and NA genes, the influenza A genome contains eight genes encoding 11 proteins. These proteins include three RNA polymerases that function together as a complex required by the virus to replicate its RNA genome.

What are HA and NA proteins?

The HA and NA surface proteins of influenza viruses are “antigens,” which means they are recognized by the immune system and are capable of triggering an immune response, including production of antibodies that can block infection.

How many ha and NA proteins are there in influenza?

There are 18 known HA subtypes and 11 known NA subtypes. Many different combinations of HA and NA proteins are possible. For example, an “H7N2 virus” designates an influenza A virus subtype that has an HA 7 protein and an NA 2 protein. Similarly, an “H5N1” virus has an HA 5 protein and an NA 1 protein.

Where are the hemagglutinins found in the influenza virus?

The first three hemagglutinins, H1, H2, and H3, are found in human influenza viruses. By phylogenic similarity, the HA proteins are divided into 2 groups, with H1, H2, H5, H6, H8, H9, H11, H12, H13, H16, H17, and H18 belonging to group 1 and the rest in group 2.

What’s the difference between influenza A and C viruses?

The genomic organization of influenza C viruses is generally similar to that of influenza A and B viruses; however, the HEF protein of influenza C replaces the HA and NA proteins, and thus the influenza C virus genome has one fewer segment than that of influenza A or B viruses.

What kind of glycoprotein is found in the influenza virus?

x-ray structure of the haemagglutinin-esterase-fusion glycoprotein of influenza c virus. Influenza hemagglutinin (HA) or haemagglutinin [p] (British English) is a homotrimeric glycoprotein found on the surface of influenza viruses and is integral to its infectivity.