EC - TRNA (cytidine34-2'-O)-methyltransferase

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IntEnz Enzyme Nomenclature


Accepted name:
tRNA (cytidine34-2'-O)-methyltransferase
Other names:
ybiK (gene name)
methyltransferase yibK
tRNA methyltransferase L
tRNA (cytidine34/5-carboxymethylaminomethyluridine34-2'-O)-methyltransferase
Systematic name:
S-adenosyl-L-methionine:tRNA (cytidine34/5-carboxymethylaminomethyluridine34-2'-O)-methyltransferase



The enzyme from Escherichia coli catalyses the 2'-O-methylation of cytidine or 5-carboxymethylaminomethyluridine at the wobble position at nucleotide 34 in tRNALeuCmAA and tRNALeucmnm5UmAA. The enzyme is selective for the two tRNALeu isoacceptors and only methylates these when they present the correct anticodon loop sequence and modification pattern. Specifically, YibK requires a pyrimidine nucleoside at position 34, it has a clear preference for an adenosine at position 35, and it fails to methylate without prior addition of the N6-(isopentenyl)-2-methylthioadenosine modification at position 37.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
UniProtKB/Swiss-Prot: (26) [show] [UniProt]


  1. Benitez-Paez, A., Villarroya, M., Douthwaite, S., Gabaldon, T., Armengod, M. E.
    YibK is the 2'-O-methyltransferase TrmL that modifies the wobble nucleotide in Escherichia coli tRNALeu isoacceptors.
    RNA 16 : 2131-2143 (2010). [PMID: 20855540]

[EC created 2011]