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==Cryo-EM structure of the KdpFABC complex in an E1 outward-facing state (state 1)== | |||
<SX load='6hra' size='340' side='right' viewer='molstar' caption='[[6hra]], [[Resolution|resolution]] 3.70Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[6hra]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6HRA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6HRA FirstGlance]. <br> | |||
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.7Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=K:POTASSIUM+ION'>K</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=6hra FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6hra OCA], [https://pdbe.org/6hra PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6hra RCSB], [https://www.ebi.ac.uk/pdbsum/6hra PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6hra 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 == | |||
P-type ATPases ubiquitously pump cations across biological membranes to maintain vital ion gradients. Among those, the chimeric K(+) uptake system KdpFABC is unique. While ATP hydrolysis is accomplished by the P-type ATPase subunit KdpB, K(+) has been assumed to be transported by the channel-like subunit KdpA. A first crystal structure uncovered its overall topology, suggesting such a spatial separation of energizing and transporting units. Here, we report two cryo-EM structures of the 157 kDa, asymmetric KdpFABC complex at 3.7 A and 4.0 A resolution in an E1 and an E2 state, respectively. Unexpectedly, the structures suggest a translocation pathway through two half-channels along KdpA and KdpB, uniting the alternating-access mechanism of actively pumping P-type ATPases with the high affinity and selectivity of K(+) channels. This way, KdpFABC would function as a true chimeric complex, synergizing the best features of otherwise separately evolved transport mechanisms. | |||
Cryo-EM structures of KdpFABC suggest a K(+) transport mechanism via two inter-subunit half-channels.,Stock C, Hielkema L, Tascon I, Wunnicke D, Oostergetel GT, Azkargorta M, Paulino C, Hanelt I Nat Commun. 2018 Nov 26;9(1):4971. doi: 10.1038/s41467-018-07319-2. PMID:30478378<ref>PMID:30478378</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
[[Category: | </div> | ||
<div class="pdbe-citations 6hra" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[ATPase 3D structures|ATPase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</SX> | |||
[[Category: Escherichia coli K-12]] | |||
[[Category: Large Structures]] | |||
[[Category: Azkargorta M]] | |||
[[Category: Haenelt I]] | |||
[[Category: Hielkema L]] | |||
[[Category: Oostergetel GT]] | |||
[[Category: Paulino C]] | |||
[[Category: Stock C]] | |||
[[Category: Tascon I]] | |||
[[Category: Wunnicke D]] |