EC - 23S rRNA (guanine748-N1)-methyltransferase

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IntEnz Enzyme Nomenclature


Accepted name:
23S rRNA (guanine748-N1)-methyltransferase
Other names:
23S rRNA m1G748 methyltransferase
tylosin-resistance methyltransferase RlmA(II)
rRNA large subunit methyltransferase II
Systematic name:
S-adenosyl-L-methionine:23S rRNA (guanine748-N1)-methyltransferase



The enzyme specifically methylates guanine748 at N1 in 23S rRNA. The methyltransferase RlmAII confers resistance to the macrolide antibiotic tylosin in the drug-producing strain Streptomyces fradiae [1].

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
Gene Ontology: GO:0052912


  1. Douthwaite, S., Crain, P. F., Liu, M., Poehlsgaard, J.
    The tylosin-resistance methyltransferase RlmAII (TlrB) modifies the N-1 position of 23S rRNA nucleotide G748.
    J. Mol. Biol. 337 : 1073-1077 (2004). [PMID: 15046978]
  2. Liu, M., Kirpekar, F., Van Wezel, G. P., Douthwaite, S.
    The tylosin resistance gene tlrB of Streptomyces fradiae encodes a methyltransferase that targets G748 in 23S rRNA.
    Mol. Microbiol. 37 : 811-820 (2000). [PMID: 10972803]
  3. Lebars, I., Yoshizawa, S., Stenholm, A. R., Guittet, E., Douthwaite, S., Fourmy, D.
    Structure of 23S rRNA hairpin 35 and its interaction with the tylosin-resistance methyltransferase RlmAII.
    EMBO J. 22 : 183-192 (2003). [PMID: 12514124]
  4. Lebars, I., Husson, C., Yoshizawa, S., Douthwaite, S., Fourmy, D.
    Recognition elements in rRNA for the tylosin resistance methyltransferase RlmAII.
    J. Mol. Biol. 372 : 525-534 (2007). [PMID: 17673230]
  5. Douthwaite, S., Jakobsen, L., Yoshizawa, S., Fourmy, D.
    Interaction of the tylosin-resistance methyltransferase RlmAII at its rRNA target differs from the orthologue RlmAI.
    J. Mol. Biol. 378 : 969-975 (2008). [PMID: 18406425]
  6. Liu, M., Douthwaite, S.
    Methylation at nucleotide G748 or G748 in 23S rRNA distinguishes Gram-negative from Gram-positive bacteria.
    Mol. Microbiol. 44 : 195-204 (2002). [PMID: 11967079]

[EC created 1976 as EC, part-transferred 2010 to EC]