View source for 5mrw


==Structure of the KdpFABC complex==
<StructureSection load='5mrw' size='340' side='right'caption='[[5mrw]], [[Resolution|resolution]] 2.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5mrw]] is a 12 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5MRW OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5MRW 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=BOG:B-OCTYLGLUCOSIDE'>BOG</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=PX4:1,2-DIMYRISTOYL-SN-GLYCERO-3-PHOSPHOCHOLINE'>PX4</scene>, <scene name='pdbligand=SEP:PHOSPHOSERINE'>SEP</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=5mrw FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5mrw OCA], [https://pdbe.org/5mrw PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5mrw RCSB], [https://www.ebi.ac.uk/pdbsum/5mrw PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5mrw ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/KDPA_ECOLI KDPA_ECOLI] Part of the high-affinity ATP-driven potassium transport (or Kdp) system, which catalyzes the hydrolysis of ATP coupled with the electrogenic transport of potassium into the cytoplasm (PubMed:2849541, PubMed:8499455, PubMed:23930894). This subunit binds and transports the potassium across the cytoplasmic membrane (PubMed:7896809).<ref>PMID:23930894</ref> <ref>PMID:2849541</ref> <ref>PMID:7896809</ref> <ref>PMID:8499455</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Cellular potassium import systems play a fundamental role in osmoregulation, pH homeostasis and membrane potential in all domains of life. In bacteria, the kdp operon encodes a four-subunit potassium pump that maintains intracellular homeostasis, cell shape and turgor under conditions in which potassium is limiting. This membrane complex, called KdpFABC, has one channel-like subunit (KdpA) belonging to the superfamily of potassium transporters and another pump-like subunit (KdpB) belonging to the superfamily of P-type ATPases. Although there is considerable structural and functional information about members of both superfamilies, the mechanism by which uphill potassium transport through KdpA is coupled with ATP hydrolysis by KdpB remains poorly understood. Here we report the 2.9 A X-ray structure of the complete Escherichia coli KdpFABC complex with a potassium ion within the selectivity filter of KdpA and a water molecule at a canonical cation site in the transmembrane domain of KdpB. The structure also reveals two structural elements that appear to mediate the coupling between these two subunits. Specifically, a protein-embedded tunnel runs between these potassium and water sites and a helix controlling the cytoplasmic gate of KdpA is linked to the phosphorylation domain of KdpB. On the basis of these observations, we propose a mechanism that repurposes protein channel architecture for active transport across biomembranes.

Crystal structure of the potassium-importing KdpFABC membrane complex.,Huang CS, Pedersen BP, Stokes DL Nature. 2017 Jun 29;546(7660):681-685. doi: 10.1038/nature22970. Epub 2017 Jun, 21. PMID:28636601<ref>PMID:28636601</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 5mrw" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Huang C]]
[[Category: Pedersen BP]]
[[Category: Stokes DL]]