View source for 3nn9


==REFINED ATOMIC STRUCTURES OF N9 SUBTYPE INFLUENZA VIRUS NEURAMINIDASE AND ESCAPE MUTANTS==
<StructureSection load='3nn9' size='340' side='right'caption='[[3nn9]], [[Resolution|resolution]] 2.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3nn9]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Unidentified_influenza_virus Unidentified influenza virus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3NN9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3NN9 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.3&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BMA:BETA-D-MANNOSE'>BMA</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=3nn9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3nn9 OCA], [https://pdbe.org/3nn9 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3nn9 RCSB], [https://www.ebi.ac.uk/pdbsum/3nn9 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3nn9 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/NRAM_I75A5 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.
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/nn/3nn9_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=3nn9 ConSurf].
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== Publication Abstract from PubMed ==
The crystal structure of the N9 subtype neuraminidase of influenza virus was refined by simulated annealing and conventional techniques to an R-factor of 0.172 for data in the resolution range 6.0 to 2.2 A. The r.m.s. deviation from ideal values of bond lengths is 0.014 A. The structure is similar to that of N2 subtype neuraminidase both in secondary structure elements and in their connections. The three-dimensional structures of several escape mutants of neuraminidase, selected with antineuraminidase monoclonal antibodies, are also reported. In every case, structural changes associated with the point mutation are confined to the mutation site or to residues that are spatially immediately adjacent to it. The failure of antisera to cross-react between N2 and N9 subtypes may be correlated with the absence of conserved, contiguous surface structures of area 700 A2 or more.

Refined atomic structures of N9 subtype influenza virus neuraminidase and escape mutants.,Tulip WR, Varghese JN, Baker AT, van Donkelaar A, Laver WG, Webster RG, Colman PM J Mol Biol. 1991 Sep 20;221(2):487-97. PMID:1920429<ref>PMID:1920429</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Neuraminidase 3D structures|Neuraminidase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Unidentified influenza virus]]
[[Category: Baker AT]]
[[Category: Colman PM]]
[[Category: Laver WG]]
[[Category: Tulip WR]]
[[Category: Vandonkelaar A]]
[[Category: Varghese JN]]
[[Category: Webster RG]]