EC - TRNAIle-lysidine synthetase

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IntEnz Enzyme Nomenclature


Accepted name:
tRNAIle-lysidine synthetase
Other names:
mesJ (gene name)
yacA (gene name)
isoleucine-specific transfer ribonucleate lysidine synthetase
Systematic name:
L-lysine:[tRNAIle2]-cytidine34 ligase (AMP-forming)



The bacterial enzyme modifies the wobble base of the CAU anticodon of tRNAIle at the oxo group in position 2 of cytidine34. This modification determines both codon and amino acid specificities of tRNAIle.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
UniProtKB/Swiss-Prot: (323) [show] [UniProt]


  1. Ikeuchi, Y., Soma, A., Ote, T., Kato, J., Sekine, Y., Suzuki, T.
    Molecular mechanism of lysidine synthesis that determines tRNA identity and codon recognition.
    Mol. Cell 19: 235-246 (2005). [PMID: 16039592]
  2. Salowe, S. P., Wiltsie, J., Hawkins, J. C., Sonatore, L. M.
    The catalytic flexibility of tRNAIle-lysidine synthetase can generate alternative tRNA substrates for isoleucyl-tRNA synthetase.
    J. Biol. Chem. 284: 9656-9662 (2009). [PMID: 19233850]
  3. Nakanishi, K., Fukai, S., Ikeuchi, Y., Soma, A., Sekine, Y., Suzuki, T., Nureki, O.
    Structural basis for lysidine formation by ATP pyrophosphatase accompanied by a lysine-specific loop and a tRNA-recognition domain.
    Proc. Natl. Acad. Sci. USA 102: 7487-7492 (2005). [PMID: 15894617]
  4. Soma, A., Ikeuchi, Y., Kanemasa, S., Kobayashi, K., Ogasawara, N., Ote, T., Kato, J., Watanabe, K., Sekine, Y., Suzuki, T.
    An RNA-modifying enzyme that governs both the codon and amino acid specificities of isoleucine tRNA.
    Mol. Cell 12: 689-698 (2003). [PMID: 14527414]
  5. Nakanishi, K., Bonnefond, L., Kimura, S., Suzuki, T., Ishitani, R., Nureki, O.
    Structural basis for translational fidelity ensured by transfer RNA lysidine synthetase.
    Nature 461: 1144-1148 (2009). [PMID: 19847269]

[EC created 2011]