View source for 5avq


==Kinetics by X-ray crystallography: Tl+-substitution of bound K+ in the E2.MgF42-.2K+ crystal after 0.75 min.==
<StructureSection load='5avq' size='340' side='right'caption='[[5avq]], [[Resolution|resolution]] 2.60&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5avq]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Squalus_acanthias Squalus acanthias]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5AVQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5AVQ 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]] 2.6&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CLR:CHOLESTEROL'>CLR</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=MF4:TETRAFLUOROMAGNESATE(2-)'>MF4</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=TL:THALLIUM+(I)+ION'>TL</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=5avq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5avq OCA], [https://pdbe.org/5avq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5avq RCSB], [https://www.ebi.ac.uk/pdbsum/5avq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5avq ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q4H132_SQUAC Q4H132_SQUAC] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Na(+),K(+)-ATPase transfers three Na(+) from the cytoplasm into the extracellular medium and two K(+) in the opposite direction per ATP hydrolysed. The binding and release of Na(+) and K(+) are all thought to occur sequentially. Here we demonstrate by X-ray crystallography of the ATPase in E2.MgF4(2-).2K(+), a state analogous to E2.Pi.2K(+), combined with isotopic measurements, that the substitution of the two K(+) with congeners in the extracellular medium indeed occurs at different rates, substantially faster at site II. An analysis of thermal movements of protein atoms in the crystal shows that the M3-M4E helix pair opens and closes the ion pathway leading to the extracellular medium, allowing K(+) at site II to be substituted first. Taken together, these results indicate that site I K(+) is the first cation to bind to the empty cation-binding sites after releasing three Na(+).

Sequential substitution of K(+) bound to Na(+),K(+)-ATPase visualized by X-ray crystallography.,Ogawa H, Cornelius F, Hirata A, Toyoshima C Nat Commun. 2015 Aug 10;6:8004. doi: 10.1038/ncomms9004. PMID:26258479<ref>PMID:26258479</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5avq" style="background-color:#fffaf0;"></div>

==See Also==
*[[ATPase 3D structures|ATPase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Squalus acanthias]]
[[Category: Cornelius F]]
[[Category: Hirata A]]
[[Category: Ogawa H]]
[[Category: Toyoshima C]]