View source for 1ncc


==CRYSTAL STRUCTURES OF TWO MUTANT NEURAMINIDASE-ANTIBODY COMPLEXES WITH AMINO ACID SUBSTITUTIONS IN THE INTERFACE==
<StructureSection load='1ncc' size='340' side='right'caption='[[1ncc]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1ncc]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Influenza_a_virus Influenza a virus] and [https://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NCC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1NCC FirstGlance]. <br>
</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=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</scene></td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Exo-alpha-sialidase Exo-alpha-sialidase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.18 3.2.1.18] </span></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=1ncc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ncc OCA], [https://pdbe.org/1ncc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ncc RCSB], [https://www.ebi.ac.uk/pdbsum/1ncc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ncc ProSAT]</span></td></tr>
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== 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/nc/1ncc_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.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=1ncc ConSurf].
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== Publication Abstract from PubMed ==
The site on influenza virus N9 neuraminidase recognized by NC41 monoclonal antibody comprises 19 amino acid residues that are in direct contact with 17 residues on the antibody. Single sequence changes in some of the neuraminidase residues in the site markedly reduce antibody binding. However, two mutants have been found within the site, Ile368 to Arg and Asn329 to Asp selected by antibodies other than NC41, and these mutants bind NC41 antibody with only slightly reduced affinity. The three-dimensional structures of the two mutant N9-NC41 antibody complexes as derived from the wild-type complex are presented. Both structures show that some amino acid substitutions can be accommodated within an antigen-antibody interface by local structural rearrangements around the mutation site. In the Ile368 to Arg mutant complex, the side-chain of Arg368 is shifted by 2.9 A from its position in the uncomplexed mutant and a shift of 1.3 A in the position of the light chain residue HisL55 with respect to the wild-type complex is also observed. In the other mutant, the side-chain of Asp329 appears rotated by 150 degrees around C alpha-C beta with respect to the uncomplexed mutant, so that the carboxylate group is moved to the periphery of the antigen-antibody interface. The results provide a basis for understanding some of the potential structural effects of somatic hypermutation on antigen-antibody binding in those cases where the mutation in the antibody occurs at antigen-contacting residues, and demonstrate again the importance of structural context in evaluating the effect of amino acid substitutions on protein structure and function.

Crystal structures of two mutant neuraminidase-antibody complexes with amino acid substitutions in the interface.,Tulip WR, Varghese JN, Webster RG, Laver WG, Colman PM J Mol Biol. 1992 Sep 5;227(1):149-59. PMID:1522584<ref>PMID:1522584</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Antibody 3D structures|Antibody 3D structures]]
*[[Neuraminidase 3D structures|Neuraminidase 3D structures]]
*[[3D structures of non-human antibody|3D structures of non-human antibody]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Exo-alpha-sialidase]]
[[Category: Influenza a virus]]
[[Category: Large Structures]]
[[Category: Mus musculus]]
[[Category: Colman, P M]]
[[Category: Tulip, W R]]
[[Category: Varghese, J N]]