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==X-ray structure of the metastable SEPT14-SEPT7 heterodimeric coiled coil==
<StructureSection load='8sjj' size='340' side='right'caption='[[8sjj]], [[Resolution|resolution]] 1.78&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8sjj]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8SJJ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8SJJ 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]] 1.781&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=PEG:DI(HYDROXYETHYL)ETHER'>PEG</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=8sjj FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8sjj OCA], [https://pdbe.org/8sjj PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8sjj RCSB], [https://www.ebi.ac.uk/pdbsum/8sjj PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8sjj ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/SEP14_HUMAN SEP14_HUMAN] Gliosarcoma;Giant cell glioblastoma. 
== Function ==
[https://www.uniprot.org/uniprot/SEP14_HUMAN SEP14_HUMAN] Filament-forming cytoskeletal GTPase (Probable). Involved in the migration of cortical neurons and the formation of neuron leading processes during embryonic development (By similarity). Plays a role in sperm head formation during spermiogenesis, potentially via facilitating localization of ACTN4 to cell filaments (PubMed:33228246).[UniProtKB:Q9DA97]<ref>PMID:33228246</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Septins are membrane-associated, GTP-binding proteins that are present in most eukaryotes. They polymerize to play important roles as scaffolds and/or diffusion barriers as part of the cytoskeleton. alpha-Helical coiled-coil domains are believed to contribute to septin assembly, and those observed in both human SEPT6 and SEPT8 form antiparallel homodimers. These are not compatible with their parallel heterodimeric organization expected from the current model for protofilament assembly, but they could explain the interfilament cross-bridges observed by microscopy. Here, the first structure of a heterodimeric septin coiled coil is presented, that between SEPT14 and SEPT7; the former is a SEPT6/SEPT8 homolog. This new structure is parallel, with two long helices that are axially shifted by a full helical turn with reference to their sequence alignment. The structure also has unusual knobs-into-holes packing of side chains. Both standard seven-residue (heptad) and the less common 11-residue (hendecad) repeats are present, creating two distinct regions with opposite supercoiling, which gives rise to an overall straight coiled coil. Part of the hendecad region is required for heterodimerization and therefore may be crucial for selective septin recognition. These unconventional sequences and structural features produce a metastable heterocomplex that nonetheless has enough specificity to promote correct protofilament assembly. For instance, the lack of supercoiling may facilitate unzipping and transitioning to the antiparallel homodimeric state.

X-ray structure of the metastable SEPT14-SEPT7 coiled coil reveals a hendecad region crucial for heterodimerization.,Cavini IA, Winter AJ, D'Muniz Pereira H, Woolfson DN, Crump MP, Garratt RC Acta Crystallogr D Struct Biol. 2023 Oct 1. doi: 10.1107/S2059798323006514. PMID:37712436<ref>PMID:37712436</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8sjj" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Cavini IA]]
[[Category: Garratt RC]]
[[Category: Pereira HM]]