Format

Send to

Choose Destination
See comment in PubMed Commons below
RNA. 2004 Jun;10(6):907-13.

A novel partial modification at C2501 in Escherichia coli 23S ribosomal RNA.

Author information

  • 1Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.

Abstract

Escherichia coli is the best-characterized organism with respect to posttranscriptional modifications of its ribosomal RNA (rRNA). It is presently believed that all the modified nucleotides have been identified, primarily on the basis of two detection methods; modification-induced inhibition of the enzyme reverse transcriptase or analysis by combined HPLC and electrospray ionization mass spectrometry. Comparison of data from these different approaches reveals a disagreement regarding modification of C2501 in E. coli 23S rRNA. A. Bakin and J. Ofengand previously reported the detection of a modification at this site based on a reverse transcriptase assay. J.A. McCloskey and coworkers could not confirm the existence of such a modification using an electrospray ionization mass spectrometry approach. C2501 is therefore generally considered unmodified. We have used a strategy involving isolation of a specific rRNA fragment from E. coli 23S rRNA followed by Matrix Assisted Laser Desorption/Ionization mass spectrometry and tandem mass spectrometry to investigate this controversy. Our data reveal a novel 16-Da partial modification at C2501. We believe that the data reported here clarify the above discrepancy, because a minor partial modification detected in a reverse transcriptase assay would not necessarily be detected by the original mass spectrometry approach. The level of modification was furthermore monitored in different growth situations, and we found a significant positive regulation in stationary phase cells. C2501 is universally conserved and implicated in structure folds very close to the catalytic center of the ribosome. Moreover, several antibiotics bind to nucleotides in this region, which altogether make a modification at this site interesting.

PMID:
15146074
PMCID:
PMC1370582
[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Support Center