title: Cleavage and isomerization of UpU promoted by dinuclear metal ion complexes.
abstract: The catalysis of phosphoryl transfer by metal ions has been intensively studied in both biological and artificial systems, but the status of the transient pentacoordinate phosphoryl species (as transition state or intermediate) is the subject of considerable debate. We report that dinuclear metal ion complexes that incorporate second sphere hydrogen bond donors not only promote the cleavage of RNA fragments just as efficiently as the activated analogue HPNPP but also provide the first examples of metal ion catalyzed phosphate diester isomerization close to neutral pH. This observation implies that the reaction catalyzed by these complexes involves the formation of a phosphorane intermediate that is sufficiently long-lived to pseudorotate.
authors.affiliation: Department of Chemistry, FI-20014 University of Turku, Turku, Finland.
authors.forename: Heidi
authors.initials: H
authors.lastname: Linjalahti
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Feng
authors.forename: Juan C
authors.initials: JC
authors.lastname: Mareque-Rivas
authors.forename: Satu
authors.initials: S
authors.lastname: Mikkola
authors.forename: Nicholas H
authors.initials: NH
authors.lastname: Williams
mesh_terms: D002384:Catalysis; D003500:Cyclization; D007477:Ions / Q000737:chemistry; D007536:Isomerism; D008024:Ligands; D019216:Metals, Heavy / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010755:Organophosphates / Q000737:chemistry*; D012313:RNA / Q000737:chemistry*; D014542:Uridine Monophosphate / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
chemical_list: D007477:Ions; D008024:Ligands; D019216:Metals, Heavy; D009942:Organometallic Compounds; D010755:Organophosphates; D012313:RNA; D014542:Uridine Monophosphate; D015032:Zinc