5hum
The crystal structure of neuraminidase from A/Sichuan/26221/2014 influenza virus
Structural highlights
FunctionA0A0B4N5Z5_9INFA Catalyzes the removal of terminal sialic acid residues from viral and cellular glycoconjugates. Cleaves off the terminal sialic acids on the glycosylated HA during virus budding to facilitate virus release. Additionally helps virus spread through the circulation by further removing sialic acids from the cell surface. These cleavages prevent self-aggregation and ensure the efficient spread of the progeny virus from cell to cell. Otherwise, infection would be limited to one round of replication. Described as a receptor-destroying enzyme because it cleaves a terminal sialic acid from the cellular receptors. May facilitate viral invasion of the upper airways by cleaving the sialic acid moities on the mucin of the airway epithelial cells. Likely to plays a role in the budding process through its association with lipid rafts during intracellular transport. May additionally display a raft-association independent effect on budding. Plays a role in the determination of host range restriction on replication and virulence. Sialidase activity in late endosome/lysosome traffic seems to enhance virus replication.[HAMAP-Rule:MF_04071] Publication Abstract from PubMedDuring 2014, a subclade 2.3.4.4 HPAI A(H5N8) virus caused poultry outbreaks around the world. In late 2014/early 2015 the virus was detected in wild birds in Canada and the U.S. and these viruses also gave rise to reassortant progeny, composed of viral RNA segments (vRNAs) from both Eurasian and North America lineages. In particular, viruses were found with N1, N2 and N8 neuraminidase vRNAs, and are collectively referred to as H5Nx viruses. In the U. S., more than 48 million domestic birds have been affected. Here, we present a detailed structural and biochemical analysis of the surface antigens from H5N1, H5N2 and H5N8 in addition to a recent human H5N6 virus. Our results with recombinant hemagglutinin reveal that these viruses have a strict avian receptor binding preference, while recombinantly expressed neuraminidases are sensitive to FDA approved and investigational antivirals. Although H5Nx viruses currently pose a low risk to humans, it is important to maintain surveillance of these circulating viruses, and to continually assess future changes that may increase their pandemic potential. IMPORTANCE: The H5Nx viruses emerging in North America, Europe, and Asia are of great public health concern. Herein, we report a molecular and structural study of the major surface proteins from several H5Nx influenza viruses. Our results improve the understanding of these new viruses and provide important information on their receptor preference and susceptibility to antivirals, which is central to pandemic risk assessment. The molecular characterizations of surface proteins hemagglutinin and neuraminidase from recent H5Nx avian influenza viruses.,Yang H, Carney PJ, Mishin VP, Guo Z, Chang JC, Wentworth DE, Gubareva LV, Stevens J J Virol. 2016 Apr 6. pii: JVI.00180-16. PMID:27053557[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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