Previous Article | Next Article ![]()
J Bacteriol, June 1998, p. 2883-2888, Vol. 180, No. 11
Department of Medicinal Chemistry, University
of Utah, Salt Lake City, Utah 84112,1 and
Department of Biochemistry, University of Utah, Salt Lake City,
Utah 841322
Received 18 February 1998/Accepted 25 March 1998
Posttranscriptional modification is common to many types of RNA,
but the majority of information concerning structure and function of
modification is derived principally from tRNA. By contrast, less is
known about modification in rRNA in spite of accumulating evidence for
its direct participation in translation. The structural identities and
approximate molar levels of modifications have been established for 16S
and 23S rRNAs of the archaeal hyperthermophile Sulfolobus
solfactaricus by using combined chromatography-mass spectrometry-based methods. Modification levels are exceptionally high
for prokaryotic organisms, with approximately 38 modified sites in 16S
rRNA and 50 in 23S rRNA for cells cultured at 75°C, compared with 11 and 23 sites, respectively, in Escherichia coli. We
structurally characterized 10 different modified nucleosides in 16S
rRNA, 64% (24 residues) of which are methylated at O-2' of ribose, and
8 modified species in 23S rRNA, 86% (43 residues) of which are ribose
methylated, a form of modification shown in earlier studies to enhance
stability of the polynucleotide chain. From cultures grown at
progressively higher temperatures, 60, 75, and 83°C, a slight trend
toward increased ribose methylation levels was observed, with greatest
net changes over the 23°C range shown for
2'-O-methyladenosine in 16S rRNA (21% increase) and for
2'-O-methylcytidine (24%) and
2'-O-methylguanosine (22%) in 23S rRNA. These findings are
discussed in terms of the potential role of modification in
stabilization of rRNA in the thermal environment.
0021-9193/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
Posttranscriptional Modifications in 16S and 23S
rRNAs of the Archaeal Hyperthermophile Sulfolobus
solfataricus
*
Corresponding author. Mailing address: 311A Skaggs
Hall, University of Utah, 30 So. 2000 East, Salt Lake City, UT 84112. Phone: (801) 581-5582. Fax: (801) 581-7457. E-mail:
james.mccloskey{at}m.cc.utah.edu.
This article has been cited by other articles:
| Appl. Environ. Microbiol. | Infect. Immun. | Eukaryot. Cell |
|---|---|---|
| Mol. Cell. Biol. | J. Virol. | Microbiol. Mol. Biol. Rev. |
| ALL ASM JOURNALS |