JB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Evguenieva-Hackenberg, E.
Right arrow Articles by Klug, G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Evguenieva-Hackenberg, E.
Right arrow Articles by Klug, G.

Journal of Bacteriology, September 2000, p. 4719-4729, Vol. 182, No. 17
0021-9193/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.

RNase III Processing of Intervening Sequences Found in Helix 9 of 23S rRNA in the Alpha Subclass of Proteobacteria

Elena Evguenieva-Hackenberg* and Gabriele Klug

Institut für Mikro- und Molekularbiologie der Justus-Liebig-Universität Giessen, 35392 Giessen, Germany

Received 22 February 2000/Accepted 7 June 2000

We provide experimental evidence for RNase III-dependent processing in helix 9 of the 23S rRNA as a general feature of many species in the alpha subclass of Proteobacteria (alpha-Proteobacteria). We investigated 12 Rhodobacter, Rhizobium, Sinorhizobium, Rhodopseudomonas, and Bartonella strains. The processed region is characterized by the presence of intervening sequences (IVSs). The 23S rDNA sequences between positions 109 and 205 (Escherichia coli numbering) were determined, and potential secondary structures are proposed. Comparison of the IVSs indicates very different evolutionary rates in some phylogenetic branches, lateral genetic transfer, and evolution by insertion and/or deletion. We show that the IVS processing in Rhodobacter capsulatus in vivo is RNase III-dependent and that RNase III cleaves additional sites in vitro. While all IVS-containing transcripts tested are processed in vitro by RNase III from R. capsulatus, E. coli RNase III recognizes only some of them as substrates and in these substrates frequently cleaves at different scissile bonds. These results demonstrate the different substrate specificities of the two enzymes. Although RNase III plays an important role in the rRNA, mRNA, and bacteriophage RNA maturation, its substrate specificity is still not well understood. Comparison of the IVSs of helix 9 does not hint at sequence motives involved in recognition but reveals that the "antideterminant" model, which represents the most recent attempt to explain the E. coli RNase III specificity in vitro, cannot be applied to substrates derived from alpha-Proteobacteria.

* Corresponding author. Mailing address: Institut für Mikro- und Molekularbiologie der Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 26, 35392 Giessen, Germany. Phone: 49-641-99-35550/57. Fax: 49-641-99-35549. E-mail: Elena.Evguenieva-Hackenberg{at}mikro.bio.uni-giessen.de.

Journal of Bacteriology, September 2000, p. 4719-4729, Vol. 182, No. 17
0021-9193/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Appl. Environ. Microbiol. Infect. Immun. Eukaryot. Cell
Mol. Cell. Biol. J. Virol. Microbiol. Mol. Biol. Rev.
ALL ASM JOURNALS

Copyright © 2000 by the American Society for Microbiology. All rights reserved.