title: A complement to the modern crystallographer's toolbox: caged gadolinium complexes with versatile binding modes.
abstract: A set of seven caged gadolinium complexes were used as vectors for introducing the chelated Gd(3+) ion into protein crystals in order to provide strong anomalous scattering for de novo phasing. The complexes contained multidentate ligand molecules with different functional groups to provide a panel of possible interactions with the protein. An exhaustive crystallographic analysis showed them to be nondisruptive to the diffraction quality of the prepared derivative crystals, and as many as 50% of the derivatives allowed the determination of accurate phases, leading to high-quality experimental electron-density maps. At least two successful derivatives were identified for all tested proteins. Structure refinement showed that the complexes bind to the protein surface or solvent-accessible cavities, involving hydrogen bonds, electrostatic and CH-π interactions, explaining their versatile binding modes. Their high phasing power, complementary binding modes and ease of use make them highly suitable as a heavy-atom screen for high-throughput de novo structure determination, in combination with the SAD method. They can also provide a reliable tool for the development of new methods such as serial femtosecond crystallography.
authors.affiliation: University Grenoble Alpes, Institut de Biologie Structurale (IBS), Grenoble, France.
authors.forename: Meike
authors.initials: M
authors.lastname: Stelter
authors.affiliation: Structural Biology and Biocomputing Programme, Spanish Cancer Research Centre (CNIO), Melchor Fdez Almagro, 28029 Madrid, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Molina
authors.affiliation: Laboratoire Information Génomique et Structurale, CNRS - UMR7256, Institut de Microbiologie de la Méditerranée, 163 Avenue de Luminy, 13288 Marseille CEDEX 09, France.
authors.forename: Sandra
authors.initials: S
authors.lastname: Jeudy
authors.affiliation: University Grenoble Alpes, Institut de Biologie Structurale (IBS), Grenoble, France.
authors.forename: Richard
authors.initials: R
authors.lastname: Kahn
authors.affiliation: Laboratoire Information Génomique et Structurale, CNRS - UMR7256, Institut de Microbiologie de la Méditerranée, 163 Avenue de Luminy, 13288 Marseille CEDEX 09, France.
authors.forename: Chantal
authors.initials: C
authors.lastname: Abergel
authors.affiliation: Departamento de Cristalografía y Biología Estructural, Instituto Química Física Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain.
authors.forename: Juan A
authors.initials: JA
authors.lastname: Hermoso
mesh_terms: D001665:Binding Sites; D018360:Crystallography, X-Ray / Q000379:methods*; D005682:Gadolinium / Q000737:chemistry*; D015394:Molecular Structure
chemical_list: D005682:Gadolinium
keywords: Gd complexes; anomalous scattering; experimental phasing