IUBMB Enzyme Nomenclature


Accepted name: tRNAIle2-agmatinylcytidine synthase

Reaction: ATP + agmatine + [tRNAIle2]-cytidine34 + H2O = [tRNAIle2]-2-agmatinylcytidine34 + AMP + 2 phosphate

Other name(s): TiaS; AF2259; tRNAIle-2-agmatinylcytidine synthetase; tRNAIle-agm2C synthetase; tRNAIle-agmatidine synthetase

Systematic name: agmatine:[tRNAIle]-cytidine34 ligase

Comments: The enzyme from the archaeon Archaeoglobus fulgidus modifies the wobble base of the CAU anticodon of the archaeal tRNAIle2 at the oxo group in position 2 of cytidine34. This modification is crucial for accurate decoding of the genetic code. In bacteria EC, tRNAIle-lysidine synthase, catalyses the modification of [tRNAIle2]-cytidine34 to [tRNAIle2]-lysidine34.

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


1. Ikeuchi, Y., Kimura, S., Numata, T., Nakamura, D., Yokogawa, T., Ogata, T., Wada, T., Suzuki, T. and Suzuki, T. Agmatine-conjugated cytidine in a tRNA anticodon is essential for AUA decoding in archaea. Nat. Chem. Biol. 6 (2010) 277-282. [PMID: 20139989]

2. Terasaka, N., Kimura, S., Osawa, T., Numata, T. and Suzuki, T. Biogenesis of 2-agmatinylcytidine catalyzed by the dual protein and RNA kinase TiaS. Nat. Struct. Mol. Biol. 18 (2011) 1268-1274. [PMID: 22002222]

3. Osawa, T., Inanaga, H., Kimura, S., Terasaka, N., Suzuki, T. and Numata, T. Crystallization and preliminary X-ray diffraction analysis of an archaeal tRNA-modification enzyme, TiaS, complexed with tRNA(Ile2) and ATP. Acta Crystallogr. Sect. F Struct. Biol. Cryst. Commun. 67 (2011) 1414-1416. [PMID: 22102245]

[EC created 2013]

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