9O5U

CryoEM structure of Siamese algae-eater influenza-like virus (SAEILV) NA

Summary for 9O5U

• Entry DOI: 10.2210/pdb9o5u/pdb
• EMDB information: 70148
• Descriptor: Neuraminidase, 2-acetamido-2-deoxy-beta-D-glucopyranose (2 entities in total)
• Functional Keywords: siamese algae-eater influenza-like virus, saeilv, flu neuraminidase, na, virus, hydrolase
• Biological source: Siamese algae-eater influenza-like virus
• Total number of polymer chains: 4
• Total formula weight: 201161.64

Authors

Huang, J.,Han, J.,Ward, A.B. (deposition date: 2025-04-10, release date: 2025-08-06)

Primary citation

Singh, G.,Huang, J.,Bhavsar, D.,Vasilev, K.,Ferguson, J.A.,Boons, G.J.,Simon, V.,de Vries, R.P.,Han, J.,Ward, A.,Krammer, F.
Characterization of the glycoproteins of novel fish influenza B-like viruses.
Biorxiv, 2025

PubMed Abstract: Novel influenza-like virus sequences previously identified in fish and amphibians were found to cluster as a sister clade of influenza B viruses, but have thus far remained uncharacterized. We demonstrate that salamander influenza-like virus (SILV) HA is functionally divergent from influenza B virus HA and does not bind to α 2,3- and α2,6-linked sialic acids. However, the HAs of Siamese algae-eater influenza-like virus (SAEILV) and chum salmon influenza-like virus (CSILV) bind to α2,3 linked sialic acid. Furthermore, SAEILV HA binds to sialyated Lewis X, is activated by human airway enzymes and is fusogenic at a wide range of pH conditions. SAEILV NA has a highly conserved active site and a similar structure to other known NAs. We also determined the cryo-electron microscopy structure of the HA of a previously described virus from the same sister clade, the Wuhan spiny eel influenza virus (WSEIV). Importantly, no cross-reactive antibodies against these HAs or NAs were found in the human serum, suggesting that humans are immunologically naïve to these viruses.

PubMed: 40654808
DOI: 10.1101/2025.05.08.652883

Experimental method

ELECTRON MICROSCOPY (2.75 Å)