View source for 4s1x


==Crystal structure of HA2-Del-L2seM, Central Coiled-Coil from Influenza Hemagglutinin HA2 without Heptad Repeat Stutter==
<StructureSection load='4s1x' size='340' side='right'caption='[[4s1x]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4s1x]] is a 6 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=4S1X OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4S1X 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]] 1.9&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</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=4s1x FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4s1x OCA], [https://pdbe.org/4s1x PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4s1x RCSB], [https://www.ebi.ac.uk/pdbsum/4s1x PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4s1x ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The coiled-coil is one of the most ubiquitous and well studied protein structural motifs. Significant effort has been devoted to dissecting subtle variations of the typical heptad repeat sequence pattern that can designate larger topological features such as relative alpha-helical orientation and oligomer size. Here we report the X-ray structure of a model coiled-coil peptide, HA2-Del-L2seM, which forms an unanticipated core antiparallel dimer with potential sites for discrete higher-order multimerization (trimer or tetramer). In the X-ray structure, a third, partially-ordered alpha-helix is weakly associated with the antiparallel dimer and analytical ultracentrifugation experiments indicate the peptide forms a well-defined tetramer in solution. The HA2-Del-L2seM sequence is closely related to a parent model peptide, HA2-Del, which we previously reported adopts a parallel trimer; HA2-Del-L2seM differs by only hydrophobic leucine to selenomethione mutations and thus this subtle difference is sufficient to switch both relative alpha-helical topology and number of alpha-helices participating in the coiled-coil. Comparison of the X-ray structures of HA2-Del-L2seM (reported here) with the HA2-Del parent (reported previously) reveals novel interactions involving the selenomethionine residues that promote antiparallel coiled-coil configuration and preclude parallel trimer formation. These novel atomic insights are instructive for understanding subtle features that can affect coiled-coil topology and provide additional information for design of antiparallel coiled-coils. This article is protected by copyright. All rights reserved.

A Switch from Parallel to Antiparallel Strand Orientation in a Coiled-Coil X-Ray Structure via Two Core Hydrophobic Mutations.,Malashkevich VN, Higgins CD, Almo SC, Lai JR Biopolymers. 2015 Mar 6. doi: 10.1002/bip.22631. PMID:25753192<ref>PMID:25753192</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4s1x" style="background-color:#fffaf0;"></div>

==See Also==
*[[Hemagglutinin 3D structures|Hemagglutinin 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Unidentified influenza virus]]
[[Category: Almo SC]]
[[Category: Higgins CD]]
[[Category: Lai JR]]
[[Category: Malashkevich VN]]