title: Mutant ATP-binding RNA aptamers reveal the structural basis for ligand binding.
abstract: The solution structure of the ATP-binding RNA aptamer has recently been determined by NMR spectroscopy. The three-dimensional fold of the molecule is determined to a large extent by stacking and hydrogen bond interactions. In the course of the structure determination it was discovered that several highly conserved nucleotides in the binding pocket can be substituted while retaining binding under NMR conditions. These surprising findings allow a closer look at the interactions that determine stability and specificity of the aptamer as well as local structural features of the molecule. The binding properties of ATP binder mutants and modified ligand molecules are explored using NMR spectroscopy, column binding studies and molecular modeling. We present additional evidence and new insights regarding the network of hydrogen bonds that defines the structure and determines stability and specificity of the aptamer.
authors.affiliation: Department of Chemistry and Biochemistry and the Molecular Biology Institute, University of California at Los Angeles, 405 Hilgard Ave, Los Angeles, CA 90095, USA.
authors.forename: T
authors.initials: T
authors.lastname: Dieckmann
authors.forename: S E
authors.initials: SE
authors.lastname: Butcher
authors.forename: M
authors.initials: M
authors.lastname: Sassanfar
authors.forename: J W
authors.initials: JW
authors.lastname: Szostak
authors.forename: J
authors.initials: J
authors.lastname: Feigon
mesh_terms: D000249:Adenosine Monophosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism*; D001665:Binding Sites; D003854:Deoxyribonucleotides / Q000737:chemistry; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D012313:RNA / Q000737:chemistry* / Q000235:genetics
chemical_list: D003854:Deoxyribonucleotides; D008024:Ligands; D000249:Adenosine Monophosphate; D012313:RNA; D000255:Adenosine Triphosphate