What are the proteins of influenza?
Influenza A viruses are divided into subtypes based on two proteins on the surface of the virus: hemagglutinin (H) and neuraminidase (N).
What protein does influenza bind to?
To infect cells without getting stuck in the mucus, influenza A relies on a balance between two proteins on the surface of its viral particles: the receptor-binding protein hemagglutinin (HA) and the cleaving protein neuraminidase (NA).
What is the genetic material in influenza?
All influenza viruses consist of single-stranded RNA as opposed to dual-stranded DNA. The RNA genes of influenza viruses are made up of chains of nucleotides that are bonded together and coded by the letters A, C, G and U, which stand for adenine, cytosine, guanine, and uracil, respectively.
What is the structure of the influenza virus genome?
The genome of influenza A viruses consists of eight single-stranded RNA segments, and the viral particle has two major glycoproteins on its surface: hemagglutinin and neuraminidase. Figure courtesy of M-T.
What two proteins are present on the envelope of influenza viruses?
Outer virus particle The envelope is covered with glycoproteins HA and NA which form structures like spikes. The ratio of HA to NA molecules is about four to one.
How does influenza bind to cell?
Abstract. Influenza A virus (IAV) binds its host cell using the major viral surface protein hemagglutinin (HA). HA recognizes sialic acid, a plasma membrane glycan that functions as the specific primary attachment factor (AF).
What are two of the most important surface proteins found on the influenza virus?
Two proteins (hemagglutinin and neuraminidase) on the surface of influenza viruses contain the major antigens targeted by antibodies (see Figure 1).
What are the accessory proteins of influenza B?
The eight segments of the influenza A virus genome code for the viral proteins (Table 1). The three largest segments each encode one of the viral polymerase subunits, PB2, PB1, and PA. The second segment also encodes an accessory protein, PB1-F2, from an alternate open reading frame within the PB1 gene.
What is the role of N neuraminidase proteins of influenza viruses?
Influenza A viruses generally mediate binding to cell surface sialic acid receptors via the hemagglutinin (HA) glycoprotein, with the neuraminidase (NA) glycoprotein being responsible for cleaving the receptor to allow virus release.
What structure on the influenza virus provides attachment to the surface of the targeted host cell?
The influenza viral spike that attaches to the cell receptor is the HA protein – hemagglutinin. The cell receptor is sialic acid – a small sugar that is attached to many different proteins on the cell surface.