A cis-dominant regulatory mutation linked to the argB-argC gene cluster in Saccharomyces cerevisiae
| Autor: | Marcelle Grenson, Jean Claude Jauniaux, Philippe Jacobs |
|---|---|
| Rok vydání: | 1980 |
| Předmět: |
Genetics
Transcription Genetic biology Operon Phosphotransferases Saccharomyces cerevisiae Attenuator (genetics) Regulatory site Arginine biology.organism_classification Aldehyde Oxidoreductases Glutamates Structural Biology Transcription (biology) Genes Regulator Mutation Gene cluster biology.protein RNA Messenger Molecular Biology Gene Acetylglutamate kinase |
| Zdroj: | Journal of Molecular Biology. 139:691-704 |
| ISSN: | 0022-2836 |
| Popis: | The argB-argC gene cluster of Saccharomyces cerevisiae , a genetic unit of coordinate expression, is presented as a good tool for investigating the possibility of eucaryotic cells producing more than a single polypeptide directly from one polycistronic messenger RNA. This conclusion is based on the following. The argB-argC gene cluster is transcribed as a single messenger RNA molecule, starting from the argB end (Minet et al. , 1979). New data are presented supporting the idea that two separate proteins, N -acetylglutamate kinase and N -acetylglutamylphosphate reductase, are produced in vivo from the argB-argC gene cluster. Further evidence is provided that the low levels of both enzyme activities in arginine-grown cells are due to repression rather than to inactivation of the enzymes. A regulatory mutation has been isolated which specifically affects the expression of the argB-argC gene cluster. It is tightly linked to the cluster and close to the argB end, the putative origin of transcription. It is cis -dominant in heterozygous diploids. It does not qualitatively affect the affinity constants of N -acetylglutamate kinase and N -acetylglutamylphosphate reductase for their respective main substrates. Additional characteristics are described showing that the mutation most probably affects an operator or attenuator site, or any other regulatory site with analogous properties controlling arginine repression on the argB-argC gene cluster. The data are consistent with several interpretations. 1. (1) The argB-argC gene cluster of S. cerevisiae is translated into a single polypeptide and subsequently processed in vivo into two distinct proteins by a specialized cutting mechanism. 2. (2) The cluster is organized as a bacterial operon. 3. (3) The dicistronic mRNA corresponding to the cluster is processed into two pieces, each of which is read independently. |
| Databáze: | OpenAIRE |
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