title: Gadolinium tagging for high-precision measurements of 6 nm distances in protein assemblies by EPR.
abstract: Double electron-electron resonance (DEER) distance measurements of a protein complex tagged with two Gd(3+) chelates developed for rigid positioning of the metal ion are shown to deliver outstandingly accurate distance measurements in the 6 nm range. The accuracy was assessed by comparison with modeled distance distributions based on the three-dimensional molecular structures of the protein and the tag and further comparison with paramagnetic NMR data. The close agreement between the predicted and experimentally measured distances opens new possibilities for investigating the structure of biomolecular assemblies. As an example, we show that the dimer interface of rat ERp29 in solution is the same as that determined previously for human ERp29 in the single crystal.
authors.affiliation: Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia.
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Yagi
authors.forename: Debamalya
authors.initials: D
authors.lastname: Banerjee
authors.forename: Bim
authors.initials: B
authors.lastname: Graham
authors.forename: Thomas
authors.initials: T
authors.lastname: Huber
authors.forename: Daniella
authors.initials: D
authors.lastname: Goldfarb
authors.forename: Gottfried
authors.initials: G
authors.lastname: Otting
mesh_terms: D000818:Animals; D018360:Crystallography, X-Ray; D004578:Electron Spin Resonance Spectroscopy; D005682:Gadolinium / Q000737:chemistry*; D006360:Heat-Shock Proteins / Q000737:chemistry* / Q000235:genetics; D006801:Humans; D009154:Mutation; D019906:Nuclear Magnetic Resonance, Biomolecular; D017433:Protein Structure, Secondary; D051381:Rats
chemical_list: C491738:ERP29 protein, human; C110909:Erp29 protein, rat; D006360:Heat-Shock Proteins; D005682:Gadolinium