2yn9: Difference between revisions
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==Cryo-EM structure of gastric H+,K+-ATPase with bound rubidium== | |||
<StructureSection load='2yn9' size='340' side='right'caption='[[2yn9]], [[Resolution|resolution]] 8.00Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[2yn9]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2YN9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2YN9 FirstGlance]. <br> | |||
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron crystallography, [[Resolution|Resolution]] 8Å</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=2yn9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2yn9 OCA], [https://pdbe.org/2yn9 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2yn9 RCSB], [https://www.ebi.ac.uk/pdbsum/2yn9 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2yn9 ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/ATP4A_PIG ATP4A_PIG] Catalyzes the hydrolysis of ATP coupled with the exchange of H(+) and K(+) ions across the plasma membrane. Responsible for acid production in the stomach. | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Gastric H(+),K(+)-ATPase is responsible for gastric acid secretion. ATP-driven H(+) uptake into the stomach is efficiently accomplished by the exchange of an equal amount of K(+), resulting in a luminal pH close to 1. Because of the limited free energy available for ATP hydrolysis, the stoichiometry of transported cations is thought to vary from 2H(+)/2K(+) to 1H(+)/1K(+) per hydrolysis of one ATP molecule as the luminal pH decreases, although direct evidence for this hypothesis has remained elusive. Here, we show, using the phosphate analog aluminum fluoride (AlF) and a K(+) congener (Rb(+)), the 8-A resolution structure of H(+),K(+)-ATPase in the transition state of dephosphorylation, (Rb(+))E2 approximately AlF, which is distinct from the preceding Rb(+)-free E2P state. A strong density located in the transmembrane cation-binding site of (Rb(+))E2 approximately AlF highly likely represents a single bound Rb(+) ion, which is clearly different from the Rb(+)-free E2AlF or K(+)-bound (K(+))E2 approximately AlF structures. Measurement of radioactive (86)Rb(+) binding suggests that the binding stoichiometry varies depending on the pH, and approximately half of the amount of Rb(+) is bound under acidic crystallization conditions compared with at a neutral pH. These data represent structural and biochemical evidence for the 1H(+)/1K(+)/1ATP transport mode of H(+),K(+)-ATPase, which is a prerequisite for generation of the 10(6)-fold proton gradient in terms of thermodynamics. Together with the released E2P-stabilizing interaction between the beta subunit's N terminus and the P domain observed in the (Rb(+))E2 approximately AlF structure, we propose a refined vectorial transport model of H(+),K(+)-ATPase, which must prevail against the highly acidic state of the gastric lumen. | |||
Cryo-EM structure of gastric H+,K+-ATPase with a single occupied cation-binding site.,Abe K, Tani K, Friedrich T, Fujiyoshi Y Proc Natl Acad Sci U S A. 2012 Nov 6;109(45):18401-6. doi:, 10.1073/pnas.1212294109. Epub 2012 Oct 22. PMID:23091039<ref>PMID:23091039</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 2yn9" style="background-color:#fffaf0;"></div> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Sus scrofa]] | |||
[[Category: Abe K]] | |||
[[Category: Friedrich T]] | |||
[[Category: Fujiyoshi Y]] | |||
[[Category: Tani K]] | |||