title: Role of tautomerism in RNA biochemistry.
abstract: Heterocyclic nucleic acid bases and their analogs can adopt multiple tautomeric forms due to the presence of multiple solvent-exchangeable protons. In DNA, spontaneous formation of minor tautomers has been speculated to contribute to mutagenic mispairings during DNA replication, whereas in RNA, minor tautomeric forms have been proposed to enhance the structural and functional diversity of RNA enzymes and aptamers. This review summarizes the role of tautomerism in RNA biochemistry, specifically focusing on the role of tautomerism in catalysis of small self-cleaving ribozymes and recognition of ligand analogs by riboswitches. Considering that the presence of multiple tautomers of nucleic acid bases is a rare occurrence, and that tautomers typically interconvert on a fast time scale, methods for studying rapid tautomerism in the context of nucleic acids under biologically relevant aqueous conditions are also discussed.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Vipender
authors.initials: V
authors.lastname: Singh
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Bogdan I
authors.initials: BI
authors.lastname: Fedeles
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA jessig@mit.edu.
authors.forename: John M
authors.initials: JM
authors.lastname: Essigmann
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry; D001665:Binding Sites; D055162:Biocatalysis; D007536:Isomerism; D008958:Models, Molecular; D010084:Oxidation-Reduction; D012313:RNA / Q000737:chemistry; D016337:RNA, Catalytic / Q000737:chemistry*; D058928:Riboswitch
chemical_list: D052157:Aptamers, Nucleotide; D016337:RNA, Catalytic; D058928:Riboswitch; D012313:RNA
keywords: RNA; riboswitches; ribozymes; tautomerism