This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Cameron, D. M. Articles by Dahlberg, A. E. Search for Related Content PubMed PubMed Citation Articles by Cameron, D. M. Articles by Dahlberg, A. E.

 Previous Article  |  Next Article 

Journal of Bacteriology, September 2004, p. 5819-5825, Vol. 186, No. 17
0021-9193/04/$08.00+0     DOI: 10.1128/JB.186.17.5819-5825.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

Thermus thermophilus L11 Methyltransferase, PrmA, Is Dispensable for Growth and Preferentially Modifies Free Ribosomal Protein L11 Prior to Ribosome Assembly

Dale M. Cameron,^1, Steven T. Gregory,¹ Jill Thompson,¹ Moo-Jin Suh,² Patrick A. Limbach,² and Albert E. Dahlberg^1*

Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island,¹ Rieveschl Laboratories for Mass Spectrometry, Department of Chemistry, University of Cincinnati, Cincinnati, Ohio²

Received 4 March 2004/ Accepted 2 June 2004

The ribosomal protein L11 in bacteria is posttranslationally trimethylated at multiple amino acid positions by the L11 methyltransferase PrmA, the product of the prmA gene. The role of L11 methylation in ribosome function or assembly has yet to be determined, although the deletion of Escherichia coli prmA has no apparent phenotype. We have constructed a mutant of the extreme thermophile Thermus thermophilus in which the prmA gene has been disrupted with the htk gene encoding a heat-stable kanamycin adenyltransferase. This mutant shows no growth defects, indicating that T. thermophilus PrmA, like its E. coli homolog, is dispensable. Ribosomes prepared from this mutant contain unmethylated L11, as determined by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), and are effective substrates for in vitro methylation by cloned and purified T. thermophilus PrmA. MALDI-TOF MS also revealed that T. thermophilus L11 contains a total of 12 methyl groups, in contrast to the 9 methyl groups found in E. coli L11. Finally, we found that, as with the E. coli methyltransferase, the ribosomal protein L11 dissociated from ribosomes is a more efficient substrate for in vitro methylation by PrmA than intact 70S ribosomes, suggesting that methylation in vivo occurs on free L11 prior to its incorporation into ribosomes.

Present address: Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA 94143.

This article has been cited by other articles:

• Sadaie, M., Shinmyozu, K., Nakayama, J.-i. (2008). A Conserved SET Domain Methyltransferase, Set11, Modifies Ribosomal Protein Rpl12 in Fission Yeast. J. Biol. Chem. 283: 7185-7195 [Abstract] [Full Text]  
• Carr, J. F., Hamburg, D.-M., Gregory, S. T., Limbach, P. A., Dahlberg, A. E. (2006). Effects of streptomycin resistance mutations on posttranslational modification of ribosomal protein s12.. J. Bacteriol. 188: 2020-2023 [Abstract] [Full Text]