7et1

Cryo-EM structure of the gastric proton pump K791S/E820D/Y340N/E936V/Y799W mutant in K+-occluded (K+)E2-AlF state

spinqualitylabelsall models 7et1, resolution 2.60Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 7et1 is a 2 chain structure with sequence from Sus scrofa. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 2.6Å Ligands: ALF, CLR, K, MG, NAG, PCW Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT 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 H(+),K(+)-ATPase mediates electroneutral exchange of 1H(+)/1K(+) per ATP hydrolysed across the membrane. Previous structural analysis of the K(+)-occluded E2-P transition state of H(+),K(+)-ATPase showed a single bound K(+) at cation-binding site II, in marked contrast to the two K(+) ions occluded at sites I and II of the closely-related Na(+),K(+)-ATPase which mediates electrogenic 3Na(+)/2K(+) translocation across the membrane. The molecular basis of the different K(+) stoichiometry between these K(+)-counter-transporting pumps is elusive. We show a series of crystal structures and a cryo-EM structure of H(+),K(+)-ATPase mutants with changes in the vicinity of site I, based on the structure of the sodium pump. Our step-wise and tailored construction of the mutants finally gave a two-K(+) bound H(+),K(+)-ATPase, achieved by five mutations, including amino acids directly coordinating K(+) (Lys791Ser, Glu820Asp), indirectly contributing to cation-binding site formation (Tyr340Asn, Glu936Val), and allosterically stabilizing K(+)-occluded conformation (Tyr799Trp). This quintuple mutant in the K(+)-occluded E2-P state unambiguously shows two separate densities at the cation-binding site in its 2.6 A resolution cryo-EM structure. These results offer new insights into how two closely-related cation pumps specify the number of K(+) accommodated at their cation-binding site. Gastric proton pump with two occluded K(+) engineered with sodium pump-mimetic mutations.,Abe K, Yamamoto K, Irie K, Nishizawa T, Oshima A Nat Commun. 2021 Sep 29;12(1):5709. doi: 10.1038/s41467-021-26024-1. PMID:34588453 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also ATPase 3D structures

Proteopedia Page Contributors and Editors (what is this?)

OCA