Structural highlights
6jxk is a 4 chain structure with sequence from Pig. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
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| Ligands: | , , , , |
| Gene: | ATP4A (PIG), ATP4B (PIG) |
| Activity: | H(+)/K(+)-exchanging ATPase, with EC number 7.2.2.19 |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Disease
[ATP4B_PIG] Note=Parietal cell autoantigen associated with autoimmune gastritis.
Function
[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.
Publication Abstract from PubMed
The gastric proton pump (H(+),K(+)-ATPase), a P-type ATPase responsible for gastric acidification, mediates electro-neutral exchange of H(+) and K(+) coupled with ATP hydrolysis, but with an as yet undetermined transport stoichiometry. Here we show crystal structures at a resolution of 2.5 A of the pump in the E2-P transition state, in which the counter-transporting cation is occluded. We found a single K(+) bound to the cation-binding site of the H(+),K(+)-ATPase, indicating an exchange of 1H(+)/1K(+) per hydrolysis of one ATP molecule. This fulfills the energy requirement for the generation of a six pH unit gradient across the membrane. The structural basis of K(+) recognition is resolved and supported by molecular dynamics simulations, establishing how the H(+),K(+)-ATPase overcomes the energetic challenge to generate an H(+) gradient of more than a million-fold-one of the highest cation gradients known in mammalian tissue-across the membrane.
A single K(+)-binding site in the crystal structure of the gastric proton pump.,Yamamoto K, Dubey V, Irie K, Nakanishi H, Khandelia H, Fujiyoshi Y, Abe K Elife. 2019 Aug 22;8. pii: 47701. doi: 10.7554/eLife.47701. PMID:31436534[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Yamamoto K, Dubey V, Irie K, Nakanishi H, Khandelia H, Fujiyoshi Y, Abe K. A single K(+)-binding site in the crystal structure of the gastric proton pump. Elife. 2019 Aug 22;8. pii: 47701. doi: 10.7554/eLife.47701. PMID:31436534 doi:http://dx.doi.org/10.7554/eLife.47701
