User:Jaime Prilusky/Scrolling seeded
From Proteopedia
Crystal structure of the sodium - potassium pump in the E2.2K+.Pi state
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| 2zxe, resolution 2.40Å () | |||||||||
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| Ligands: | , , , , , | ||||||||
| Related: | 1wpg | ||||||||
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| Resources: | FirstGlance, OCA, RCSB, PDBsum | ||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||
Sodium-potassium ATPase is an ATP-powered ion pump that establishes concentration gradients for Na(+) and K(+) ions across the plasma membrane in all animal cells by pumping Na(+) from the cytoplasm and K(+) from the extracellular medium. Such gradients are used in many essential processes, notably for generating action potentials. Na(+), K(+)-ATPase is a member of the P-type ATPases, which include sarcoplasmic reticulum Ca(2+)-ATPase and gastric H(+), K(+)-ATPase, among others, and is the target of cardiac glycosides. Here we describe a crystal structure of this important ion pump, from shark rectal glands, consisting of alpha- and beta-subunits and a regulatory FXYD protein, all of which are highly homologous to human ones. The ATPase was fixed in a state analogous to E2.2K(+).P(i), in which the ATPase has a high affinity for K(+) and still binds P(i), as in the first crystal structure of pig kidney enzyme at 3.5 A resolution. Clearly visualized now at 2.4 A resolution are coordination of K(+) and associated water molecules in the transmembrane binding sites and a phosphate analogue (MgF(4)(2-)) in the phosphorylation site. The crystal structure shows that the beta-subunit has a critical role in K(+) binding (although its involvement has previously been suggested) and explains, at least partially, why the homologous Ca(2+)-ATPase counter-transports H(+) rather than K(+), despite the coordinating residues being almost identical.
Crystal structure of the sodium-potassium pump at 2.4 A resolution., Shinoda T, Ogawa H, Cornelius F, Toyoshima C, Nature. 2009 May 21;459(7245):446-50. PMID:19458722
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
About this Structure
2ZXE is a 3 chains structure with sequences from Squalus acanthias. The October 2009 RCSB PDB Molecule of the Month feature on Sodium-Potassium Pump by David Goodsell is 10.2210/rcsb_pdb/mom_2009_10. Full crystallographic information is available from OCA.
Reference
- Shinoda T, Ogawa H, Cornelius F, Toyoshima C. Crystal structure of the sodium-potassium pump at 2.4 A resolution. Nature. 2009 May 21;459(7245):446-50. PMID:19458722 doi:10.1038/nature07939
Page seeded by OCA on Thu Jan 21 08:52:59 2010
Categories: RCSB PDB Molecule of the Month | Sodium-Potassium Pump | Squalus acanthias | Cornelius, F. | Ogawa, H. | Shinoda, T. | Toyoshima, C. | Atp-binding | Atpase | Haloacid dehydrogenease superfamily | Hydrolase | Hydrolase/transport protein complex | Ion pump | Ion transport | K+ binding | Membrane protein | Nucleotide-binding | Phosphate analogue | Phosphoprotein
