title: The Kink Turn, a Key Architectural Element in RNA Structure.
abstract: Kink turns (k-turns) are widespread structural elements that introduce an axial bend into duplex RNA with an included angle of 50°. These mediate key tertiary interactions and bind specific proteins including members of the L7Ae family. The standard k-turn comprises a three-nucleotide bulge followed by G·A and A·G pairs. The RNA kinks by an association of the two minor grooves, stabilized by the formation of a number of key cross-strand hydrogen bonds mostly involving the adenine bases of the G·A and A·G pairs. The k-turns may be divided into two conformational classes, depending on the receptor for one of these hydrogen bonds. k-turns become folded by one of three different processes. Some, but not all, k-turns become folded in the presence of metal ions. Whether or not a given k-turn is folded under these conditions is determined by its sequence. We present a set of rules for the prediction of folding properties and the structure adopted on local sequence.
authors.affiliation: Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, The University of Dundee, Dow Street, Dundee DD1 5EH, United Kingdom.
authors.forename: Lin
authors.initials: L
authors.lastname: Huang
authors.affiliation: Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, The University of Dundee, Dow Street, Dundee DD1 5EH, United Kingdom. Electronic address: d.m.j.lilley@dundee.ac.uk.
authors.forename: David M J
authors.initials: DMJ
authors.lastname: Lilley
mesh_terms: D006860:Hydrogen Bonding; D007477:Ions / Q000737:chemistry; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009711:Nucleotides / Q000737:chemistry; D011485:Protein Binding; D012313:RNA / Q000737:chemistry*; D017423:Sequence Analysis, RNA
chemical_list: D007477:Ions; D009711:Nucleotides; D012313:RNA
keywords: RNA folding; RNA–protein interaction; k-turn; metal ions; tertiary interactions