title: Metals, motifs, and recognition in the crystal structure of a 5S rRNA domain.
abstract: Two new RNA structures portray how non-Watson-Crick base pairs and metal ions can produce a unique RNA shape suitable for recognition by proteins. The crystal structures of a 62 nt domain of E. coli 5S ribosomal RNA and a duplex dodecamer encompassing an internal loop E have been determined at 3.0 and 1.5 A, respectively. This loop E region is distorted by three "cross-strand purine stacks" and three novel, water-mediated noncanonical base pairs and stabilized by a four metal ion zipper. These features give its minor groove a unique hydrogen-bonding surface and make the adjacent major groove wide enough to permit recognition by the ribosomal protein L25, which is expected to bind to this surface.
authors.affiliation: Department of Molecular Biophysics and Biochemistry, Yale University, Howard Hughes Medical Institute, New Haven, Connecticut 06520-8114, USA.
authors.forename: C C
authors.initials: CC
authors.lastname: Correll
authors.forename: B
authors.initials: B
authors.lastname: Freeborn
authors.forename: P B
authors.initials: PB
authors.lastname: Moore
authors.forename: T A
authors.initials: TA
authors.lastname: Steitz
mesh_terms: D003432:Cross-Linking Reagents; D003461:Crystallography; D004926:Escherichia coli / Q000737:chemistry; D007477:Ions; D008670:Metals / Q000737:chemistry*; D009690:Nucleic Acid Conformation; D011687:Purines / Q000737:chemistry; D012341:RNA, Ribosomal, 5S / Q000737:chemistry*
chemical_list: D003432:Cross-Linking Reagents; D007477:Ions; D008670:Metals; D011687:Purines; D012341:RNA, Ribosomal, 5S