View source for 4jf7


==Structure of the parainfluenza virus 5 (PIV5) hemagglutinin-neuraminidase (HN) ectodomain==
<StructureSection load='4jf7' size='340' side='right'caption='[[4jf7]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4jf7]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Simian_virus_5_(strain_W3) Simian virus 5 (strain W3)]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4JF7 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4JF7 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><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>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=4jf7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4jf7 OCA], [https://pdbe.org/4jf7 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4jf7 RCSB], [https://www.ebi.ac.uk/pdbsum/4jf7 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4jf7 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/HN_PIV5 HN_PIV5] Attaches the virus to sialic acid-containing cell receptors and thereby initiating infection. Binding of HN protein to the receptor induces a conformational change that allows the F protein to trigger virion/cell membranes fusion (By similarity).  Neuraminidase activity ensures the efficient spread of the virus by dissociating the mature virions from the neuraminic acid containing glycoproteins.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Paramyxoviruses cause a wide variety of human and animal diseases. They infect host cells using the coordinated action of two surface glycoproteins, the receptor binding protein (HN, H, or G) and the fusion protein (F). HN binds sialic acid on host cells (hemagglutinin activity) and hydrolyzes these receptors during viral egress (neuraminidase activity, NA). Additionally, receptor binding is thought to induce a conformational change in HN that subsequently triggers major refolding in homotypic F, resulting in fusion of virus and target cell membranes. HN is an oligomeric type II transmembrane protein with a short cytoplasmic domain and a large ectodomain comprising a long helical stalk and large globular head domain containing the enzymatic functions (NA domain). Extensive biochemical characterization has revealed that HN-stalk residues determine F specificity and activation. However, the F/HN interaction and the mechanisms whereby receptor binding regulates F activation are poorly defined. Recently, a structure of Newcastle disease virus (NDV) HN ectodomain revealed the heads (NA domains) in a "4-heads-down" conformation whereby two of the heads form a symmetrical interaction with two sides of the stalk. The interface includes stalk residues implicated in triggering F, and the heads sterically shield these residues from interaction with F (at least on two sides). Here we report the x-ray crystal structure of parainfluenza virus 5 (PIV5) HN ectodomain in a "2-heads-up/2-heads-down" conformation where two heads (covalent dimers) are in the "down position," forming a similar interface as observed in the NDV HN ectodomain structure, and two heads are in an "up position." The structure supports a model in which the heads of HN transition from down to up upon receptor binding thereby releasing steric constraints and facilitating the interaction between critical HN-stalk residues and F.

Structure of the Parainfluenza Virus 5 (PIV5) Hemagglutinin-Neuraminidase (HN) Ectodomain.,Welch BD, Yuan P, Bose S, Kors CA, Lamb RA, Jardetzky TS PLoS Pathog. 2013 Aug;9(8):e1003534. doi: 10.1371/journal.ppat.1003534. Epub 2013, Aug 8. PMID:23950713<ref>PMID:23950713</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4jf7" style="background-color:#fffaf0;"></div>

==See Also==
*[[Hemagglutinin 3D structures|Hemagglutinin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Bose S]]
[[Category: Jardetzky TS]]
[[Category: Kors CA]]
[[Category: Lamb RA]]
[[Category: Welch BD]]
[[Category: Yuan P]]