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 Lütke-Eversloh, T.
Right arrow Articles by Stephanopoulos, G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Lütke-Eversloh, T.
Right arrow Articles by Stephanopoulos, G.
Agricola
Right arrow Articles by Lütke-Eversloh, T.
Right arrow Articles by Stephanopoulos, G.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, November 2005, p. 7224-7228, Vol. 71, No. 11
0099-2240/05/$08.00+0     doi:10.1128/AEM.71.11.7224-7228.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Feedback Inhibition of Chorismate Mutase/Prephenate Dehydrogenase (TyrA) of Escherichia coli: Generation and Characterization of Tyrosine-Insensitive Mutants

Tina Lütke-Eversloh and Gregory Stephanopoulos*

Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts

Received 18 May 2005/ Accepted 20 July 2005

In order to get insights into the feedback regulation by tyrosine of the Escherichia coli chorismate mutase/prephenate dehydrogenase (CM/PDH), which is encoded by the tyrA gene, feedback-inhibition-resistant (fbr) mutants were generated by error-prone PCR. The tyrAfbr mutants were selected by virtue of their resistance toward m-fluoro-D,L-tyrosine, and seven representatives were characterized on the biochemical as well as on the molecular level. The PDH activities of the purified His6-tagged TyrA proteins exhibited up to 35% of the enzyme activity of TyrAWT, but tyrosine did not inhibit the mutant PDH activities. On the other hand, CM activities of the TyrAfbr mutants were similar to those of the TyrAWT protein. Analyses of the DNA sequences of the tyrA genes revealed that tyrAfbr contained amino acid substitutions either at Tyr263 or at residues 354 to 357, indicating that these two sites are involved in the feedback inhibition by tyrosine.

* Corresponding author. Mailing address: Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave., Room 56-469, Cambridge, MA 02139. Phone: (617) 253-4583. Fax: (617) 253-3122. E-mail: gregstep{at}mit.edu.

Applied and Environmental Microbiology, November 2005, p. 7224-7228, Vol. 71, No. 11
0099-2240/05/$08.00+0     doi:10.1128/AEM.71.11.7224-7228.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Klein-Marcuschamer, D., Santos, C. N. S., Yu, H., Stephanopoulos, G. (2009). Mutagenesis of the Bacterial RNA Polymerase Alpha Subunit for Improvement of Complex Phenotypes. Appl. Environ. Microbiol. 75: 2705-2711 [Abstract] [Full Text]  
  • Chavez-Bejar, M. I., Lara, A. R., Lopez, H., Hernandez-Chavez, G., Martinez, A., Ramirez, O. T., Bolivar, F., Gosset, G. (2008). Metabolic Engineering of Escherichia coli for L-Tyrosine Production by Expression of Genes Coding for the Chorismate Mutase Domain of the Native Chorismate Mutase-Prephenate Dehydratase and a Cyclohexadienyl Dehydrogenase from Zymomonas mobilis. Appl. Environ. Microbiol. 74: 3284-3290 [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»