{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"submitter":["Abe K"],"funding":["MEXT | Japan Society for the Promotion of Science","Naito Foundation","Takeda Science Foundation","Japan Agency for Medical Research and Development","Ono Medical Research Foundation"],"pagination":["5709"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC8481561"],"repository":["biostudies-literature"],"omics_type":["Unknown"],"volume":["12(1)"],"pubmed_abstract":["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 Å 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."],"journal":["Nature communications"],"pubmed_title":["Gastric proton pump with two occluded K+ engineered with sodium pump-mimetic mutations."],"pmcid":["PMC8481561"],"funding_grant_id":["JP19am0101074","21H02426"],"pubmed_authors":["Yamamoto K","Oshima A","Irie K","Abe K","Nishizawa T"],"additional_accession":[]},"is_claimable":false,"name":"Gastric proton pump with two occluded K+ engineered with sodium pump-mimetic mutations.","description":"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 Å 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.","dates":{"release":"2021-01-01T00:00:00Z","publication":"2021 Sep","modification":"2026-06-15T04:51:38.793Z","creation":"2025-02-18T23:52:45.064Z"},"accession":"S-EPMC8481561","cross_references":{"pubmed":["34588453"],"doi":["10.1038/s41467-021-26024-1"]}}