3ixz is a 2 chain structure with sequence from Sus scrofa. 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. For a guided tour on the structure components use FirstGlance.
[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.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The gastric H(+),K(+)-ATPase is an ATP-driven proton pump responsible for generating a million-fold proton gradient across the gastric membrane. We present the structure of gastric H(+),K(+)-ATPase at 6.5 A resolution as determined by electron crystallography of two-dimensional crystals. The structure shows the catalytic alpha-subunit and the non-catalytic beta-subunit in a pseudo-E(2)P conformation. Different from Na(+),K(+)-ATPase, the N-terminal tail of the beta-subunit is in direct contact with the phosphorylation domain of the alpha-subunit. This interaction may hold the phosphorylation domain in place, thus stabilizing the enzyme conformation and preventing the reverse reaction of the transport cycle. Indeed, truncation of the beta-subunit N-terminus allowed the reverse reaction to occur. These results suggest that the beta-subunit N-terminus prevents the reverse reaction from E(2)P to E(1)P, which is likely to be relevant for the generation of a large H(+) gradient in vivo situation.
Inter-subunit interaction of gastric H+,K+-ATPase prevents reverse reaction of the transport cycle.,Abe K, Tani K, Nishizawa T, Fujiyoshi Y EMBO J. 2009 Jun 3;28(11):1637-43. Epub 2009 Apr 23. PMID:19387495[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
↑Abe K, Tani K, Nishizawa T, Fujiyoshi Y. Inter-subunit interaction of gastric H+,K+-ATPase prevents reverse reaction of the transport cycle. EMBO J. 2009 Jun 3;28(11):1637-43. Epub 2009 Apr 23. PMID:19387495 doi:10.1038/emboj.2009.102
