21. The systematic name of this enzyme class is "'tRNA-uridine uracilmutase " '. 22. These two sites catalyze the last two steps of the de novo uridine monophosphate ( UMP ) biosynthetic pathway. 23. Pseudouridylation is the ( isomerisation of the nucleoside uridine ) to the different isomeric form pseudouridine ( ? ). 24. The reaction is catalysed by, pyrimidine-nucleoside phosphorylase,, uridine phosphorylase, and, thymidine phosphorylase. 25. This enzyme is also called "'uridine diphosphoglucose-isovitexin 2 "-glucosyltransferase " '. 26. The systematic name of this enzyme class is "'uridine diphosphoglucose-limonoid glucosyltransferase " '. 27. This enzyme is also called "'uridine diphosphoglucose-vitexin 2 "-glucosyltransferase " '. 28. All on-cells showed a response to the non-specific P2 agonist uridine triphosphate ( UTP ). 29. It can be inhibited by ribonuclease inhibitor protein, by heavy metal ions, and by uridine -vanadate complexes. 30. This modification results in mismatched base-pairing between inosine and uridine , leading to the destabilization and unwinding of dsRNA.