View source for 5aw5


==Kinetics by X-ray crystallography: Rb+-substitution of bound K+ in the E2.MgF42-.2K+ crystal after 2.2 min==
<StructureSection load='5aw5' size='340' side='right'caption='[[5aw5]], [[Resolution|resolution]] 2.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5aw5]] 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=5AW5 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5AW5 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]] 2.9&#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=RB:RUBIDIUM+ION'>RB</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=5aw5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5aw5 OCA], [https://pdbe.org/5aw5 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5aw5 RCSB], [https://www.ebi.ac.uk/pdbsum/5aw5 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5aw5 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 5aw5" 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]]