title: Magnesium-binding architectures in RNA crystal structures: validation, binding preferences, classification and motif detection.
abstract: The ubiquitous presence of magnesium ions in RNA has long been recognized as a key factor governing RNA folding, and is crucial for many diverse functions of RNA molecules. In this work, Mg(2+)-binding architectures in RNA were systematically studied using a database of RNA crystal structures from the Protein Data Bank (PDB). Due to the abundance of poorly modeled or incorrectly identified Mg(2+) ions, the set of all sites was comprehensively validated and filtered to identify a benchmark dataset of 15 334 'reliable' RNA-bound Mg(2+) sites. The normalized frequencies by which specific RNA atoms coordinate Mg(2+) were derived for both the inner and outer coordination spheres. A hierarchical classification system of Mg(2+) sites in RNA structures was designed and applied to the benchmark dataset, yielding a set of 41 types of inner-sphere and 95 types of outer-sphere coordinating patterns. This classification system has also been applied to describe six previously reported Mg(2+)-binding motifs and detect them in new RNA structures. Investigation of the most populous site types resulted in the identification of seven novel Mg(2+)-binding motifs, and all RNA structures in the PDB were screened for the presence of these motifs.
authors: Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908-0736, USA Center for Structural Genomics of Infectious Diseases (CSGID) Consortium, USA Midwest Center for Structural Genomics (MCSG) Consortium, USA New York Structural Genomics Research Consortium (NYSGRC), USA.
authors: Heping
authors: H
authors: Zheng
authors: Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908-0736, USA Center for Structural Genomics of Infectious Diseases (CSGID) Consortium, USA Midwest Center for Structural Genomics (MCSG) Consortium, USA New York Structural Genomics Research Consortium (NYSGRC), USA Enzyme Function Initiative (EFI), USA.
authors: Ivan G
authors: IG
authors: Shabalin
authors: Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908-0736, USA Midwest Center for Structural Genomics (MCSG) Consortium, USA New York Structural Genomics Research Consortium (NYSGRC), USA Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, Warsaw 02-109, Poland.
authors: Katarzyna B
authors: KB
authors: Handing
authors: Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, Warsaw 02-109, Poland Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznan, Poland.
authors: Janusz M
authors: http://orcid.org/0000-0002-6633-165X
authors: JM
authors: Bujnicki
authors: Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908-0736, USA Center for Structural Genomics of Infectious Diseases (CSGID) Consortium, USA Midwest Center for Structural Genomics (MCSG) Consortium, USA New York Structural Genomics Research Consortium (NYSGRC), USA Enzyme Function Initiative (EFI), USA wladek@iwonka.med.virginia.edu.
authors: Wladek
authors: W
authors: Minor
mesh_terms: D001665:Binding Sites; D018360:Crystallography, X-Ray; D008274:Magnesium / Q000378:metabolism*; D009690:Nucleic Acid Conformation; D012313:RNA / Q000737:chemistry / Q000378:metabolism*
chemical_list: D012313:RNA; D008274:Magnesium