IUBMB Enzyme Nomenclature


Accepted name: tRNA pseudouridine55 synthase

Reaction: tRNA uridine55 = tRNA pseudouridine55

For diagram of mechanism click here.

Other name(s): TruB; aCbf5; Pus4; YNL292w (gene name); Ψ55 tRNA pseudouridine synthase; tRNA:Ψ55-synthase; tRNA pseudouridine 55 synthase; tRNA:pseudouridine-55 synthase; Ψ55 synthase; tRNA Ψ55 synthase; tRNA:Ψ55 synthase; tRNA-uridine55 uracil mutase; Pus10; tRNA-uridine54/55 uracil mutase

Systematic name: tRNA-uridine55 uracil mutase

Comments: Pseudouridine synthase TruB from Escherichia coli specifically modifies uridine55 in tRNA molecules [1]. The bifunctional archaeal enzyme also catalyses the pseudouridylation of uridine54 [6]. It is not known whether the enzyme from Escherichia coli can also act on position 54 in vitro, since this position is occupied in Escherichia coli tRNAs by thymine.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 430429-15-5


1. Nurse, K., Wrzesinski, J., Bakin, A., Lane, B.G. and Ofengand, J. Purification, cloning, and properties of the tRNA Ψ55 synthase from Escherichia coli. RNA 1 (1995) 102-112. [PMID: 7489483]

2. Becker, H.F., Motorin, Y., Planta, R.J. and Grosjean, H. The yeast gene YNL292w encodes a pseudouridine synthase (Pus4) catalyzing the formation of Ψ55 in both mitochondrial and cytoplasmic tRNAs. Nucleic Acids Res. 25 (1997) 4493-4499. [PMID: 9358157]

3. Pienkowska, J., Wrzesinski, J. and Szweykowska-Kulinska, Z. A cell-free yellow lupin extract containing activities of pseudouridine 35 and 55 synthases. Acta Biochim. Pol. 45 (1998) 745-754. [PMID: 9918501]

4. Chaudhuri, B.N., Chan, S., Perry, L.J. and Yeates, T.O. Crystal structure of the apo forms of Ψ55 tRNA pseudouridine synthase from Mycobacterium tuberculosis: a hinge at the base of the catalytic cleft. J. Biol. Chem. 279 (2004) 24585-24591. [PMID: 15028724]

5. Hoang, C., Hamilton, C.S., Mueller, E.G. and Ferre-D'Amare, A.R. Precursor complex structure of pseudouridine synthase TruB suggests coupling of active site perturbations to an RNA-sequestering peripheral protein domain. Protein Sci. 14 (2005) 2201-2206. [PMID: 15987897]

6. Gurha, P. and Gupta, R. Archaeal Pus10 proteins can produce both pseudouridine 54 and 55 in tRNA. RNA 14 (2008) 2521-2527. [PMID: 18952823]

[EC created 2011, modified 2011]

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