Influenza A virus neuraminidase subtype N1 (H5N1) (NA)

Neuraminidase is a tetrameric glycoprotein and exosialidase (EC 3.2.1.18) found on the surface of the influenza A virus, including the H5N1 subtype. Each monomer is about 470 amino acids (~60 kDa), forming a mushroom-shaped tetramer. It plays a critical role in viral pathogenesis by cleaving α-ketosidic linkages between sialic acid and adjacent sugar residues on the host cell surface and on viral glycoproteins, promoting the release and dissemination of progeny virions after budding. Neuraminidase and hemagglutinin define the subtype and antigenic profile of influenza A viruses. Its enzymatic activity is essential for viral spread and is the target of several important antiviral drugs (neuraminidase inhibitors). NA subtypes, especially N1, are closely associated with zoonotic potential and the risk of pandemic spread. Resistance, arising primarily from mutations at key active-site residues, poses an ongoing therapeutic challenge.

Other names

neuraminidaseviral neuraminidaseinfluenza virus neuraminidaseN1 neuraminidaseavian influenza neuraminidasesialidase

Competitive inhibition of the enzymatic active site, preventing cleavage of sialic acid residues and thus blocking release of viral progeny and limiting viral spread