IUBMB Enzyme Nomenclature


Accepted name: tRNA-guanine15 transglycosylase

Reaction: guanine15 in tRNA + 7-cyano-7-carbaguanine = 7-cyano-7-carbaguanine15 in tRNA + guanine

Glossary: 7-cyano-7-carbaguanine = preQ0 = 7-cyano-7-deazaguanine
archaeosine = G* = 7-amidino-7-deazaguanosine

Other name(s): tRNA transglycosylase (ambiguous); transfer ribonucleate glycosyltransferase (ambiguous); tRNA guanine15 transglycosidase; TGT (ambiguous); transfer ribonucleic acid guanine15 transglycosylase

Systematic name: tRNA-guanine15:7-cyano-7-carbaguanine tRNA-D-ribosyltransferase

Comments: Archaeal tRNAs contain the modified nucleoside archaeosine at position 15. This archaeal enzyme catalyses the exchange of guanine at position 15 of tRNA with the base preQ0, which is ultimately modified to form the nucleoside archaeosine (cf. EC [1].

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


1. Bai, Y., Fox, D.T., Lacy, J.A., Van Lanen, S.G. and Iwata-Reuyl, D. Hypermodification of tRNA in thermophilic archaea. Cloning, overexpression, and characterization of tRNA-guanine transglycosylase from Methanococcus jannaschii. J. Biol. Chem. 275 (2000) 28731-28738. [PMID: 10862614]

[EC created 2012]

Return to EC 2.4.2 home page
Return to EC 2.4 home page
Return to EC 2 home page
Return to Enzymes home page
Return to IUBMB Biochemical Nomenclature home page