This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
4aqr
From Proteopedia
(Difference between revisions)
| (6 intermediate revisions not shown.) | |||
| Line 1: | Line 1: | ||
| - | [[Image:4aqr.jpg|left|200px]] | ||
| - | + | ==Crystal structure of calmodulin in complex with the regulatory domain of a plasma-membrane Ca2+-ATPase== | |
| + | <StructureSection load='4aqr' size='340' side='right'caption='[[4aqr]], [[Resolution|resolution]] 1.95Å' scene=''> | ||
| + | == Structural highlights == | ||
| + | <table><tr><td colspan='2'>[[4aqr]] is a 3 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=4AQR OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4AQR 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]] 1.95Å</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></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=4aqr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4aqr OCA], [https://pdbe.org/4aqr PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4aqr RCSB], [https://www.ebi.ac.uk/pdbsum/4aqr PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4aqr ProSAT]</span></td></tr> | ||
| + | </table> | ||
| + | == Function == | ||
| + | [https://www.uniprot.org/uniprot/CALM7_ARATH CALM7_ARATH] Calmodulin mediates the control of a large number of enzymes, ion channels and other proteins by Ca(2+). Among the enzymes to be stimulated by the calmodulin-Ca(2+) complex are a number of protein kinases and phosphatases. Activates MPK8 in vitro.<ref>PMID:21419340</ref> | ||
| + | <div style="background-color:#fffaf0;"> | ||
| + | == Publication Abstract from PubMed == | ||
| + | Calcium ions (Ca(2+)) have an important role as secondary messengers in numerous signal transduction processes, and cells invest much energy in controlling and maintaining a steep gradient between intracellular ( approximately 0.1-micromolar) and extracellular ( approximately 2-millimolar) Ca(2+) concentrations. Calmodulin-stimulated calcium pumps, which include the plasma-membrane Ca(2+)-ATPases (PMCAs), are key regulators of intracellular Ca(2+) in eukaryotes. They contain a unique amino- or carboxy-terminal regulatory domain responsible for autoinhibition, and binding of calcium-loaded calmodulin to this domain releases autoinhibition and activates the pump. However, the structural basis for the activation mechanism is unknown and a key remaining question is how calmodulin-mediated PMCA regulation can cover both basal Ca(2+) levels in the nanomolar range as well as micromolar-range Ca(2+) transients generated by cell stimulation. Here we present an integrated study combining the determination of the high-resolution crystal structure of a PMCA regulatory-domain/calmodulin complex with in vivo characterization and biochemical, biophysical and bioinformatics data that provide mechanistic insights into a two-step PMCA activation mechanism mediated by calcium-loaded calmodulin. The structure shows the entire PMCA regulatory domain and reveals an unexpected 2:1 stoichiometry with two calcium-loaded calmodulin molecules binding to different sites on a long helix. A multifaceted characterization of the role of both sites leads to a general structural model for calmodulin-mediated regulation of PMCAs that allows stringent, highly responsive control of intracellular calcium in eukaryotes, making it possible to maintain a stable, basal level at a threshold Ca(2+) concentration, where steep activation occurs. | ||
| - | + | A bimodular mechanism of calcium control in eukaryotes.,Tidow H, Poulsen LR, Andreeva A, Knudsen M, Hein KL, Wiuf C, Palmgren MG, Nissen P Nature. 2012 Oct 21. doi: 10.1038/nature11539. PMID:23086147<ref>PMID:23086147</ref> | |
| + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
| + | </div> | ||
| + | <div class="pdbe-citations 4aqr" style="background-color:#fffaf0;"></div> | ||
| - | == | + | ==See Also== |
| - | [[ | + | *[[Calmodulin 3D structures|Calmodulin 3D structures]] |
| + | == References == | ||
| + | <references/> | ||
| + | __TOC__ | ||
| + | </StructureSection> | ||
[[Category: Arabidopsis thaliana]] | [[Category: Arabidopsis thaliana]] | ||
| - | [[Category: | + | [[Category: Large Structures]] |
| - | [[Category: Andreeva | + | [[Category: Andreeva A]] |
| - | [[Category: Hein | + | [[Category: Hein KL]] |
| - | [[Category: Nissen | + | [[Category: Nissen P]] |
| - | [[Category: Palmgren | + | [[Category: Palmgren MG]] |
| - | [[Category: Poulsen | + | [[Category: Poulsen LR]] |
| - | [[Category: Tidow | + | [[Category: Tidow H]] |
| - | + | ||
| - | + | ||
Current revision
Crystal structure of calmodulin in complex with the regulatory domain of a plasma-membrane Ca2+-ATPase
| |||||||||||
