The Pseudouridine Synthases Proceed through a Glycal Intermediate.
The pseudouridine synthases isomerize (U) in RNA to pseudouridine (Ψ), and the mechanism that they follow has long been a question of interest. The recent elucidation of a product of the mechanistic probe 5-fluorouridine that had been epimerized to the arabino isomer suggested that the Ψ synthases might operate through a glycal intermediate formed by deprotonation of C2'. When that position in substrate U is deuterated, a primary kinetic isotope effect is observed, which indisputably indicates that the proposed deprotonation occurs during the isomerization of U to Ψ and establishes the mechanism followed by the Ψ synthases.
Department of Chemistry, University of Louisville , Louisville, Kentucky 40205, United States.
Govardhan Reddy
GR
Veerareddygari
Department of Chemistry, University of Louisville , Louisville, Kentucky 40205, United States.
Sanjay K
SK
Singh
Department of Chemistry, University of Louisville , Louisville, Kentucky 40205, United States.
Eugene G
EG
Mueller
D000838:Anions / Q000737:chemistry; D002625:Chemistry, Organic / Q000379:methods*; D003460:Crystallization; D019751:Intramolecular Transferases / Q000378:metabolism*; D007700:Kinetics; D009690:Nucleic Acid Conformation; D011134:Polysaccharides / Q000737:chemistry; D020033:Protein Isoforms; D011522:Protons; D011560:Pseudouridine / Q000737:chemistry*; D012313:RNA; D014529:Uridine / Q000031:analogs & derivatives / Q000737:chemistry
D000838:Anions; D011134:Polysaccharides; D020033:Protein Isoforms; D011522:Protons; D011560:Pseudouridine; C001943:5-fluorouridine; D012313:RNA; D019751:Intramolecular Transferases; C096995:pseudouridine synthases; D014529:Uridine