Enzymatic characterization and mutational studies of TruD--the fifth family of pseudouridine synthases

Arch Biochem Biophys. 2009 Sep;489(1-2):15-9. doi: 10.1016/j.abb.2009.07.023. Epub 2009 Aug 5.


Pseudouridine (Psi) is formed through isomerization of uridine (U) catalyzed by a class of enzymes called pseudouridine synthases (PsiS). TruD is the fifth family of PsiS. Studies of the first four families (TruA, TruB, RsuA, and RluA) of PsiS reveal a conserved Asp and Tyr are critical for catalysis. However, in TruD family, the tyrosine is not conserved. In this study, we measured the enzymatic parameters for TruD in Escherichia coli, and carried out enzymatic assays for a series of single, double, and triple TruD mutants. Our studies indicate that a Glu, strictly conserved in only TruD family is likely to be the general base in TruD. We also proposed a possible distinct mechanism of TruD-catalyzed Psi formation compared to the first four families.

MeSH terms

  • Aspartic Acid / chemistry
  • Aspartic Acid / genetics
  • Aspartic Acid / metabolism
  • Catalysis
  • Escherichia coli / enzymology*
  • Escherichia coli / genetics
  • Escherichia coli Proteins / chemistry*
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism
  • Hydro-Lyases / chemistry
  • Hydro-Lyases / genetics
  • Hydro-Lyases / metabolism
  • Intramolecular Transferases / chemistry*
  • Intramolecular Transferases / genetics
  • Intramolecular Transferases / metabolism
  • Isomerism
  • Mutation
  • Tyrosine / chemistry
  • Tyrosine / genetics
  • Tyrosine / metabolism
  • Uridine / chemistry*
  • Uridine / genetics
  • Uridine / metabolism


  • Escherichia coli Proteins
  • Aspartic Acid
  • Tyrosine
  • Hydro-Lyases
  • pseudouridylate synthetase
  • Intramolecular Transferases
  • 16S RNA pseudouridine 516 synthase, E coli
  • pseudouridine synthases
  • TruD protein, E coli
  • Uridine