IUBMB Enzyme Nomenclature


Accepted name: 23S rRNA (guanine2535-N1)-methyltransferase

Reaction: S-adenosyl-L-methionine + guanine2535 in 23S rRNA = S-adenosyl-L-homocysteine + N1-methylguanine2535 in 23S rRNA

Other name(s): AviRa

Systematic name: S-adenosyl-L-methionine:23S rRNA (guanine2535-N1)-methyltransferase

Comments: Streptomyces viridochromogenes produces the antibiotic avilamycin A which binds to the 50S ribosomal subunit to inhibit protein synthesis. To protect itself from the antibiotic, Streptomyces viridochromogenes utilizes two methyltransferases, 23S rRNA (guanine2535-N1)-methyltransferase and EC [23S rRNA (uridine2479-2-O)-methyltransferase], whose actions confer avilamycin resistance to the RNA.

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


1. Treede, I., Jakobsen, L., Kirpekar, F., Vester, B., Weitnauer, G., Bechthold, A. and Douthwaite, S. The avilamycin resistance determinants AviRa and AviRb methylate 23S rRNA at the guanosine 2535 base and the uridine 2479 ribose. Mol. Microbiol. 49 (2003) 309-318. [PMID: 12828631]

2. Weitnauer, G., Gaisser, S., Trefzer, A., Stockert, S., Westrich, L., Quiros, L.M., Mendez, C., Salas, J.A. and Bechthold, A. An ATP-binding cassette transporter and two rRNA methyltransferases are involved in resistance to avilamycin in the producer organism Streptomyces viridochromogenes Tu57. Antimicrob. Agents Chemother. 45 (2001) 690-695. [PMID: 11181344]

3. Mosbacher, T.G., Bechthold, A. and Schulz, G.E. Crystal structure of the avilamycin resistance-conferring methyltransferase AviRa from Streptomyces viridochromogenes. J. Mol. Biol. 329 (2003) 147-157. [PMID: 12742024]

[EC created 2011]

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