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 arrowReprints and Permissions
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 Quan, S.
Right arrow Articles by Squires, C. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Quan, S.
Right arrow Articles by Squires, C. L.

 Previous Article  |  Next Article 

Journal of Bacteriology, March 2005, p. 1632-1638, Vol. 187, No. 5
0021-9193/05/$08.00+0     doi:10.1128/JB.187.5.1632-1638.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Transcriptional Polarity in rRNA Operons of Escherichia coli nusA and nusB Mutant Strains

Selwyn Quan,1 Ning Zhang,1 Sarah French,2 and Catherine L. Squires1*

Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts,1 Department of Microbiology, University of Virginia, Charlottesville, Virginia2

Received 23 July 2004/ Accepted 19 November 2004

Synthesis of ribosomes in Escherichia coli requires an antitermination system that modifies RNA polymerase to achieve efficient transcription of the genes specifying 16S, 23S, and 5S rRNA. This modification requires nucleotide signals in the RNA and specific transcription factors, such as NusA and NusB. Transcription of rrn operons in strains lacking the ability to produce either NusA or NusB was examined by electron microscopy. The distribution and numbers of RNA polymerase molecules on rrn operons were determined for each mutant. Compared to the wild type, the 16S gene in the nusB mutant strain had an equivalent number of RNA polymerase molecules, but the number of RNA polymerase molecules was reduced 1.4-fold for the nusA mutant. For both mutant strains, there were twofold-fewer RNA polymerase molecules on the 23S RNA gene than for the wild type. Overall, the mutant strains each had 1.6-fold-fewer RNA polymerase molecules on their rrn operons than did the wild type. To determine if decreased transcription of the 23S gene observed by electron microscopy also affected the 30S/50S ribosomal subunit ratio, ribosome profiles were examined by sucrose gradient analysis. The 30S/50S ratio increased 2.5- to 3-fold for the nus mutant strains over that for wild-type cells. Thus, strains carrying either a nusA mutation or a nusB mutation have defects in transcription of 23S rRNA.

* Corresponding author. Mailing address: Department of Molecular Biology and Microbiology, Tufts University School of Medicine, 136 Harrison Ave., Boston, MA 02111. Phone: (617) 636-6947. Fax: (617) 636-0337. E-mail: cathy.squires{at}tufts.edu.

Journal of Bacteriology, March 2005, p. 1632-1638, Vol. 187, No. 5
0021-9193/05/$08.00+0     doi:10.1128/JB.187.5.1632-1638.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Burmann, B. M., Luo, X., Rosch, P., Wahl, M. C., Gottesman, M. E. (2009). Fine tuning of the E. coli NusB:NusE complex affinity to BoxA RNA is required for processive antitermination. Nucleic Acids Res 0: gkp736v1-gkp736 [Abstract] [Full Text]  
  • Cabrera, J. E., Cagliero, C., Quan, S., Squires, C. L., Jin, D. J. (2009). Active Transcription of rRNA Operons Condenses the Nucleoid in Escherichia coli: Examining the Effect of Transcription on Nucleoid Structure in the Absence of Transertion. J. Bacteriol. 191: 4180-4185 [Abstract] [Full Text]  
  • Dennis, P. P., Ehrenberg, M., Fange, D., Bremer, H. (2009). Varying Rate of RNA Chain Elongation during rrn Transcription in Escherichia coli. J. Bacteriol. 191: 3740-3746 [Abstract] [Full Text]  
  • Klumpp, S., Hwa, T. (2008). Stochasticity and traffic jams in the transcription of ribosomal RNA: Intriguing role of termination and antitermination. Proc. Natl. Acad. Sci. USA 105: 18159-18164 [Abstract] [Full Text]  
  • Arnvig, K. B., Zeng, S., Quan, S., Papageorge, A., Zhang, N., Villapakkam, A. C., Squires, C. L. (2008). Evolutionary Comparison of Ribosomal Operon Antitermination Function. J. Bacteriol. 190: 7251-7257 [Abstract] [Full Text]  
  • Bubunenko, M., Baker, T., Court, D. L. (2007). Essentiality of Ribosomal and Transcription Antitermination Proteins Analyzed by Systematic Gene Replacement in Escherichia coli. J. Bacteriol. 189: 2844-2853 [Abstract] [Full Text]  
  • Doherty, G. P., Meredith, D. H., Lewis, P. J. (2006). Subcellular Partitioning of Transcription Factors in Bacillus subtilis. J. Bacteriol. 188: 4101-4110 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»