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 Gropp, M.
Right arrow Articles by Glaser, G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gropp, M.
Right arrow Articles by Glaser, G.

 Previous Article  |  Next Article 

Journal of Bacteriology, January 2001, p. 570-579, Vol. 183, No. 2
0021-9193/01/$04.00+0   DOI: 10.1128/JB.183.2.570-579.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.

Regulation of Escherichia coli RelA Requires Oligomerization of the C-Terminal Domain

Michal Gropp, Yael Strausz, Miriam Gross, and Gad Glaser*

Department of Cellular Biochemistry, The Hebrew University-Hadassah Medical School, Jerusalem 90101, Israel

Received 21 April 2000/Accepted 30 October 2000

The E. coli RelA protein is a ribosome-dependent (p)ppGpp synthetase that is activated in response to amino acid starvation. RelA can be dissected both functionally and physically into two domains: The N-terminal domain (NTD) (amino acids [aa] 1 to 455) contains the catalytic domain of RelA, and the C-terminal domain (CTD) (aa 455 to 744) is involved in regulating RelA activity. We used mutational analysis to localize sites important for RelA activity and control in these two domains. We inserted two separate mutations into the NTD, which resulted in mutated RelA proteins that were impaired in their ability to synthesize (p)ppGpp. When we caused the CTD in relA+ cells to be overexpressed, (p)ppGpp accumulation during amino acid starvation was negatively affected. Mutational analysis showed that Cys-612, Asp-637, and Cys-638, found in a conserved amino acid sequence (aa 612 to 638), are essential for this negative effect of the CTD. When mutations corresponding to these residues were inserted into the full-length relA gene, the mutated RelA proteins were impaired in their regulation. In attempting to clarify the mechanism through which the CTD regulates RelA activity, we found no evidence for competition for ribosomal binding between the normal RelA and the overexpressed CTD. Results from CyaA complementation experiments of the bacterial two-hybrid system fusion plasmids (G. Karimova, J. Pidoux, A. Ullmann, and D. Ladant, Proc. Natl. Acad. Sci. USA 95:5752-5756, 1998) indicated that the CTD (aa 564 to 744) is involved in RelA-RelA interactions. Our findings support a model in which RelA activation is regulated by its oligomerization state.

* Corresponding author. Mailing address: Department of Cellular Biochemistry, The Hebrew University-Hadassah Medical School, Jerusalem 90101, Israel. Phone: (972) 2-675-8168. Fax: (972) 2-641-5848. E-mail: Glaser{at}cc.huji.ac.il.

Journal of Bacteriology, January 2001, p. 570-579, Vol. 183, No. 2
0021-9193/01/$04.00+0   DOI: 10.1128/JB.183.2.570-579.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:

  • Gan, H. M., Buckley, L., Szegedi, E., Hudson, A. O., Savka, M. A. (2009). Identification of an rsh Gene from a Novosphingobium sp. Necessary for Quorum-Sensing Signal Accumulation. J. Bacteriol. 191: 2551-2560 [Abstract] [Full Text]  
  • Kim, H.-M., Ryou, S.-M., Song, W.-S., Sim, S.-H., Cha, C.-J., Han, S. H., Ha, N.-C., Kim, J.-H., Bae, J., Cunningham, P. R., Lee, K. (2009). Genetic Analysis of the Invariant Residue G791 in Escherichia coli 16S rRNA Implicates RelA in Ribosome Function. J. Bacteriol. 191: 2042-2050 [Abstract] [Full Text]  
  • Hwang, J., Inouye, M. (2008). RelA Functionally Suppresses the Growth Defect Caused by a Mutation in the G Domain of the Essential Der Protein. J. Bacteriol. 190: 3236-3243 [Abstract] [Full Text]  
  • Silva, A. J., Benitez, J. A. (2006). A Vibrio cholerae Relaxed (relA) Mutant Expresses Major Virulence Factors, Exhibits Biofilm Formation and Motility, and Colonizes the Suckling Mouse Intestine. J. Bacteriol. 188: 794-800 [Abstract] [Full Text]  
  • Candela, T., Mignot, T., Hagnerelle, X., Haustant, M., Fouet, A. (2005). Genetic analysis of Bacillus anthracis Sap S-layer protein crystallization domain. Microbiology 151: 1485-1490 [Abstract] [Full Text]  
  • Silva, A. J., Benitez, J. A. (2004). Transcriptional Regulation of Vibrio cholerae Hemagglutinin/Protease by the Cyclic AMP Receptor Protein and RpoS. J. Bacteriol. 186: 6374-6382 [Abstract] [Full Text]  
  • Mechold, U., Murphy, H., Brown, L., Cashel, M. (2002). Intramolecular Regulation of the Opposing (p)ppGpp Catalytic Activities of RelSeq, the Rel/Spo Enzyme from Streptococcus equisimilis. J. Bacteriol. 184: 2878-2888 [Abstract] [Full Text]  
  • Yang, X., Ishiguro, E. E. (2001). Involvement of the N Terminus of Ribosomal Protein L11 in Regulation of the RelA Protein of Escherichia coli. J. Bacteriol. 183: 6532-6537 [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»