6d3b

From Proteopedia

INFLUENZA VIRUS NEURAMINIDASE SUBTYPE N9 (TERN) APO FORM

Structural highlights

6d3b is a 1 chain structure with sequence from Influenza A virus (A/tern/Australia/G70C/1975(H11N9)). Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 1.4Å
Ligands:	, , , ,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

NRAM_I75A5 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.

Publication Abstract from PubMed

The influenza neuraminidase (NA) is a homotetramer with head, stalk, transmembrane and cytoplasmic regions. The structure of the NA head with a stalk has never been determined. The NA head from an N9 subtype influenza A virus, A/tern/Australia/G70C/1975 (H1N9), was expressed with an artificial stalk derived from the tetrabrachion (TB) tetramerization domain from Staphylothermus marinus. The NA was successfully crystallized both with and without the TB stalk, and the structures were determined to 2.6 and 2.3 A resolution, respectively. Comparisons of the two NAs with the native N9 NA structure from egg-grown virus showed that the artificial TB stalk maintained the native NA head structure, supporting previous biological observations.

Structure of an Influenza A virus N9 neuraminidase with a tetrabrachion-domain stalk.,Streltsov VA, Schmidt PM, McKimm-Breschkin JL Acta Crystallogr F Struct Biol Commun. 2019 Feb 1;75(Pt 2):89-97. doi:, 10.1107/S2053230X18017892. Epub 2019 Jan 23. PMID:30713159^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Streltsov VA, Schmidt PM, McKimm-Breschkin JL. Structure of an Influenza A virus N9 neuraminidase with a tetrabrachion-domain stalk. Acta Crystallogr F Struct Biol Commun. 2019 Feb 1;75(Pt 2):89-97. doi:, 10.1107/S2053230X18017892. Epub 2019 Jan 23. PMID:30713159 doi:http://dx.doi.org/10.1107/S2053230X18017892