3IXZ

Pig gastric H+/K+-ATPase complexed with aluminium fluoride

Summary for 3IXZ

• Entry DOI: 10.2210/pdb3ixz/pdb
• Related: 3B8E
• EMDB information: 5104
• Descriptor: Potassium-transporting ATPase alpha, Potassium-transporting ATPase subunit beta (2 entities in total)
• Functional Keywords: ion pump, h+, k+-atpase, p-type atpase, membrane protein, hydrolase, e2, aluminium fluoride, atp-binding, hydrogen ion transport, ion transport, magnesium, membrane, metal-binding, nucleotide-binding, phosphoprotein, potassium, potassium transport, transmembrane, transport, disulfide bond, glycoprotein, signal-anchor
• Biological source: Sus scrofa (pigs,swine,wild boar); More
• Total number of polymer chains: 2
• Total formula weight: 147513.53

Authors

Abe, K.,Tani, K.,Nishizawa, T.,Fujiyoshi, Y. (deposition date: 2009-03-09, release date: 2009-06-23, Last modification date: 2024-02-21)

Primary citation

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., 28:1637-1643, 2009

PubMed Abstract: 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.

PubMed: 19387495
DOI: 10.1038/emboj.2009.102

Experimental method

ELECTRON CRYSTALLOGRAPHY (6.5 Å)