View source for 8qmp


==Structure of the E2 Beryllium Fluoride Complex of the Autoinhibited Calcium ATPase ACA8==
<StructureSection load='8qmp' size='340' side='right'caption='[[8qmp]], [[Resolution|resolution]] 3.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8qmp]] is a 1 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=8QMP OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8QMP FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.3&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BEF:BERYLLIUM+TRIFLUORIDE+ION'>BEF</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=8qmp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8qmp OCA], [https://pdbe.org/8qmp PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8qmp RCSB], [https://www.ebi.ac.uk/pdbsum/8qmp PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8qmp ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ACA8_ARATH ACA8_ARATH] This magnesium-dependent enzyme catalyzes the hydrolysis of ATP coupled with the translocation of calcium from the cytosol out of the cell.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The autoinhibited plasma membrane calcium ATPase ACA8 from A. thaliana has an N-terminal autoinhibitory domain. Binding of calcium-loaded calmodulin at two sites located at residues 42-62 and 74-96 relieves autoinhibition of ACA8 activity. Through activity studies and a yeast complementation assay we investigated wild-type (WT) and N-terminally truncated ACA8 constructs (Delta20, Delta30, Delta35, Delta37, Delta40, Delta74 and Delta100) to explore the role of conserved motifs in the N-terminal segment preceding the calmodulin binding sites. Furthermore, we purified WT, Delta20- and Delta100-ACA8, tested activity in vitro and performed structural studies of purified Delta20-ACA8 stabilized in a lipid nanodisc to explore the mechanism of autoinhibition. We show that an N-terminal segment between residues 20 and 35 including conserved Phe32, upstream of the calmodulin binding sites, is important for autoinhibition and the activation by calmodulin. Cryo-EM structure determination at 3.3 A resolution of a beryllium fluoride inhibited E2 form, and at low resolution for an E1 state combined with AlphaFold prediction provide a model for autoinhibition, consistent with the mutational studies.

Conserved N-terminal Regulation of the ACA8 Calcium Pump with Two Calmodulin Binding Sites.,Larsen ST, Dannerso JK, Nielsen CJF, Poulsen LR, Palmgren M, Nissen P J Mol Biol. 2024 Oct 15;436(20):168747. doi: 10.1016/j.jmb.2024.168747. Epub 2024 , Aug 20. PMID:39168442<ref>PMID:39168442</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8qmp" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Arabidopsis thaliana]]
[[Category: Large Structures]]
[[Category: Karlsen Dannersoe J]]
[[Category: Nissen P]]
[[Category: Thirup Larsen S]]