Coevolution of transcriptional and allosteric regulation at the chorismate metabolic branch point of Saccharomyces cerevisiae
2000 | journal article. A publication with affiliation to the University of Göttingen.
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Coevolution of transcriptional and allosteric regulation at the chorismate metabolic branch point of Saccharomyces cerevisiae
Krappmann, S.; Lipscomb, W. N. & Braus, G. H. (2000)
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 97(25) pp. 13585-13590. DOI: https://doi.org/10.1073/pnas.240469697
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Details
- Authors
- Krappmann, Sven; Lipscomb, William N.; Braus, Gerhard H.
- Abstract
- Control of transcription and enzyme activities are two interwoven regulatory systems essential for the function of a metabolic node. Saccharomyces cerevisiae strains differing in enzyme activities at the chorismate branch point of aromatic amino acid biosynthesis were constructed by recombinant DNA technology. Expression of an allosterically unregulated, constitutively activated chorismate mutase encoded by the ARO7T(226I) (ARO7(c)) allele depleted the chorismate pool. The resulting tryptophan limitation caused growth defects, which could be counteracted only by transcriptional induction of TRP2 encoding the competing enzyme anthranilate synthase. ARO7 expression is not transcriptionally regulated by amino acids. Transcriptional activation of the ARO7(c) allele led to stronger growth retardation upon tryptophan limitation. The same effect was achieved by removing the competing enzyme anthranilate synthase, which is encoded by the TRP2 gene, from the transcriptional control. The allelic situation of ARO7(c) being under general control instead of TRP2 resulted in severe growth defects when cells were starved for tryptophan. In conclusion, the specific regulatory pattern acting on enzymatic activities at the first metabolic node of aromatic amino acid biosynthesis is necessary to maintain proper flux distribution. Therefore, the evolution of the sophisticated allosteric regulation of yeast chorismate mutase requires as prerequisite (i) that the encoding ARO7 gene is not transcriptionally regulated, whereas (ii) the transcription of the competing feedback-regulated anthranilate synthase-encoding gene is controlled by availability of amino acids.
- Issue Date
- 2000
- Status
- published
- Publisher
- Natl Acad Sciences
- Journal
- PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
- ISSN
- 0027-8424
- Sponsor
- NIGMS NIH HHS [R01 GM006920]