title: Structural characterization of proteins with an attached ATCUN motif by paramagnetic relaxation enhancement NMR spectroscopy.
abstract: The use of a short, three-residue Cu(2+)-binding sequence, the ATCUN motif, is presented as an approach for extracting long-range distance restraints from relaxation enhancement NMR spectroscopy. The ATCUN motif is prepended to the N-termini of proteins and binds Cu(2+) with a very high affinity. Relaxation rates of amide protons in ATCUN-tagged protein in the presence and absence of Cu(2+) can be converted into distance restraints and used for structure refinement by using a new routine, PMAG, that has been written for the structure calculation program CNS. The utility of the approach is demonstrated with an application to ATCUN-tagged ubiquitin. Excellent agreement between measured relaxation rates and those calculated on the basis of the X-ray structure of the protein have been obtained.
authors.affiliation: Department of Medical Genetics, University of Toronto, Toronto, ON, Canada, M5S 1A8.
authors.forename: L W
authors.initials: LW
authors.lastname: Donaldson
authors.forename: N R
authors.initials: NR
authors.lastname: Skrynnikov
authors.forename: W Y
authors.initials: WY
authors.lastname: Choy
authors.forename: D R
authors.initials: DR
authors.lastname: Muhandiram
authors.forename: B
authors.initials: B
authors.lastname: Sarkar
authors.forename: J D
authors.initials: JD
authors.lastname: Forman-Kay
authors.forename: L E
authors.initials: LE
authors.lastname: Kay
mesh_terms: D020816:Amino Acid Motifs; D001665:Binding Sites; D003300:Copper / Q000737:chemistry*; D006801:Humans; D019906:Nuclear Magnetic Resonance, Biomolecular; D011487:Protein Conformation; D013816:Thermodynamics; D025801:Ubiquitin / Q000737:chemistry* / Q000378:metabolism
chemical_list: D025801:Ubiquitin; D003300:Copper