View source for 9swt


==Middle and C-terminal domains of HSP90C from Arabidopsis thaliana==
<StructureSection load='9swt' size='340' side='right'caption='[[9swt]], [[Resolution|resolution]] 3.15&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9swt]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Arabidopsis_thaliana Arabidopsis thaliana]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9SWT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9SWT 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]] 3.15&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</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=9swt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9swt OCA], [https://pdbe.org/9swt PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9swt RCSB], [https://www.ebi.ac.uk/pdbsum/9swt PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9swt ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/HS905_ARATH HS905_ARATH] Molecular chaperone required for chloroplast biogenesis (PubMed:12943545, PubMed:25216779). Essential for chloroplast biogenesis and maintenance, and thus for embryogenesis (PubMed:23382192, PubMed:23875936). May be involved in the disassembly of VIPP1 for thylakoid membrane formation and/or maintenance (PubMed:23875936). Cooperates with TIC components and other molecular chaperones to drive transport of preproteins into chloroplasts and functions in the chloroplast stroma to facilitate membrane translocation during protein import into the organelle (PubMed:23382192).<ref>PMID:12943545</ref> <ref>PMID:23382192</ref> <ref>PMID:23875936</ref> <ref>PMID:25216779</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Chloroplasts are the main energy-producing organelles in plants, responsible for photosynthesis, CO(2) fixation, and O(2) production. These processes rely on the import of numerous nucleus-encoded proteins into the chloroplast and, eventually, the thylakoids. While translocation systems across chloroplast and thylakoid membranes are well characterized, the stromal route between these membranes remains poorly understood. The chloroplastic HSP90 (HSP90C) is likely to play a key role in this process, yet its structure and molecular mechanisms are unknown. Here, we combine structural and biophysical approaches to characterize HSP90C from Arabidopsis thaliana. We show that HSP90C displays exceptionally high ATPase activity compared with other HSP90 family members, driven by non-canonical mechanisms. These include an N-terminal disulfide bond that enhances ATPase activity and a C-terminal extension required for dimerization. These features arise from conserved sequence signatures shared among Angiospermae. Our work provides the first structural insights into HSP90C and advances understanding of chloroplast protein import mechanisms.

Structural basis of HSP90C, a highly active chloroplastic HSP90 chaperone from Arabidopsis thaliana.,La Rocca R, Chenuel T, Bergonzi C, Maes A, Pozza A, Meyer P J Mol Biol. 2026 Jul 6;438(19):169935. doi: 10.1016/j.jmb.2026.169935. PMID:42409278<ref>PMID:42409278</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9swt" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Arabidopsis thaliana]]
[[Category: Large Structures]]
[[Category: Chenuel T]]
[[Category: La Rocca R]]
[[Category: Meyer P]]