AVM

Protein name	Neuraminidase
Uniprot protein ID	C3W6G3
Protein length	469 amino acids
Protein description	The NA assembles as a tetramer of four identical polypeptides and, when embedded in the envelope of the virus, accounts for approximately 10-20% of the total glycoproteins on the virion surface, with about 40-50 NA spikes and 300-400 HA spikes on an average sized virion of 120 nm. The four monomers, each of approximately 470 amino acids, fold into four distinct structural domains: the cytoplasmic tail, the transmembrane region, the stalk, and the catalytic head. The NA 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.

Pubmed ID	30799182
Clinical information	Yes
Disease	-
Published year	2019
Journal	J Infect Public Health
Title	Atypical influenza A(H1N1)pdm09 strains caused an influenza virus outbreak in Saudi Arabia during the 2009-2025 pandemic season
Author	Anis Khan,Mohammed A AlBalwi,Ibraheem AlAbdulkareem,Abdulrahman AlMasoud,Abdulrahman AlAsiri
Evidence	E374K (E47K in HA2 subunit) was found in 9/43 (20.9%) isolates randomly distributed in the phylogenetic tree. Two out of nine cases with E47K mutation appeared to have underlying asthma along with the cardiac and renal disease. A diversity of other substitutions detected spatially or in combination with others were C538A/F/R (residue 311 in HA2 subunit) in 6/43 (13.9%), N294S in 3/43 (6.9%), D222E, I266V, D35Y/N, and S84G/N in 2/43 (4.6%) isolates. There was a case with double mutation R319K/I321G, and another one with triple mutation N31D/D35N/S84N (Fig. 2A). Mutations observed in the NAgene of Saudi isolates with respect to the prototype A/California/07/2009 are presented in Table 4 and annotated in Fig. 2B. All of the Saudi isolates possessed V106I, N248D, and residue H275 (Table 4). The novel NA mutations detected in Saudi strains were E462D in 7/43 (16.2%), I365T in 5/43 (11.6%), and N369T in 2/43 (4.6%) isolates. We did not detect amino acid substitutions A247N, I223V or R [21], known to reduce the susceptibility to NAI in Saudi isolates.