Structural highlights
5avs is a 3 chain structure with sequence from Squalus acanthias. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
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| Method: | X-ray diffraction, Resolution 2.9Å |
| Ligands: | CLR, K, MF4, MG, NAG, TL |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
Q70Q12_SQUAC
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[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Ogawa H, Cornelius F, Hirata A, Toyoshima C. Sequential substitution of K(+) bound to Na(+),K(+)-ATPase visualized by X-ray crystallography. Nat Commun. 2015 Aug 10;6:8004. doi: 10.1038/ncomms9004. PMID:26258479 doi:https://dx.doi.org/10.1038/ncomms9004
