title: Structure determination using poorly diffracting membrane-protein crystals: the H+-ATPase and Na+,K+-ATPase case history.
abstract: An approach is presented for the structure determination of membrane proteins on the basis of poorly diffracting crystals which exploits molecular replacement for heavy-atom site identification at 6-9 A maximum resolution and improvement of the heavy-atom-derived phases by multi-crystal averaging using quasi-isomorphous data sets. The multi-crystal averaging procedure allows real-space density averaging followed by phase combination between non-isomorphous native data sets to exploit crystal-to-crystal nonisomorphism despite the crystals belonging to the same space group. This approach has been used in the structure determination of H(+)-ATPase and Na(+),K(+)-ATPase using Ca(2+)-ATPase models and its successful application to the Mhp1 symporter using LeuT as a search model is demonstrated.
authors.affiliation: Centre for Membrane Pumps in Cells and Disease, Danish National Research Foundation, Aarhus University, Department of Molecular Biology, Gustav Wieds Vej 10C, DK 8000 Aarhus, Denmark.
authors.forename: Bjørn P
authors.initials: BP
authors.lastname: Pedersen
authors.forename: J Preben
authors.initials: JP
authors.lastname: Morth
authors.forename: Poul
authors.initials: P
authors.lastname: Nissen
mesh_terms: D000818:Animals; D029681:Arabidopsis Proteins / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D017434:Protein Structure, Tertiary; D006180:Proton-Translocating ATPases / Q000737:chemistry*; D000254:Sodium-Potassium-Exchanging ATPase / Q000737:chemistry*; D013552:Swine
chemical_list: D029681:Arabidopsis Proteins; D006180:Proton-Translocating ATPases; C479903:AHA2 protein, Arabidopsis; D000254:Sodium-Potassium-Exchanging ATPase