IUBMB Enzyme Nomenclature


Accepted name: pyrrolysine—tRNAPyl ligase

Reaction: ATP + L-pyrrolysine + tRNAPyl = AMP + diphosphate + L-pyrrolysyl-tRNAPyl

Glossary: pyrrolysine = N6-[(2R,3R)-3-methyl-3,4-dihydro-2H-pyrrol-2-ylcarbonyl]-L-lysine

Other name(s): PylS; pyrrolysyl-tRNA synthetase

Systematic name: L-pyrrolysine:tRNAPyl ligase (AMP-forming)

Comments: In organisms such as Methanosarcina barkeri that incorporate the modified amino acid pyrrolysine (Pyl) into certain methylamine methyltransferases, an unusual tRNAPyl, with a CUA anticodon, can be charged directly with pyrrolysine by this class II aminoacyl—tRNA ligase. The enzyme is specific for pyrrolysine as substrate as it cannot be replaced by lysine or any of the other natural amino acids [1].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:


1. Blight, S.K., Larue, R.C., Mahapatra, A., Longstaff, D.G., Chang, E., Zhao, G., Kang, P.T., Green-Church, K.B., Chan, M.K. and Krzycki, J.A. Direct charging of tRNA(CUA) with pyrrolysine in vitro and in vivo. Nature 431 (2004) 333-335. [PMID: 15329732]

2. Polycarpo, C., Ambrogelly, A., Bérubé, A., Winbush, S.M., McCloskey, J.A., Crain, P.F., Wood, J.L. and Söll, D. An aminoacyl-tRNA synthetase that specifically activates pyrrolysine. Proc. Natl. Acad. Sci. USA 101 (2004) 12450-12454. [PMID: 15314242]

3. Schimmel, P. and Beebe, K. Molecular biology: genetic code seizes pyrrolysine. Nature 431 (2004) 257-258. [PMID: 15372017]

[EC created 2007]

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