Molecular Genetics of Serine and Threonine Catabolism in Saccharomyces Cerevisiae
| Autor: | Steen Holmberg, Claus Bornaes, Morten C. Kielland-Brandt, Torsten Nilsson-Tillgren, Jens G. Litske Petersen |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1988 |
| Předmět: |
Threonine
TMPRSS6 L-Serine Dehydratase Saccharomyces cerevisiae Proteins Transcription Genetic Saccharomyces cerevisiae Mutant Genes Fungal Biology Investigations AKT3 Threonine Dehydratase Genetics Serine Cloning Molecular Regulator gene Structural gene Genetic Complementation Test Membrane Transport Proteins DNA Restriction Enzymes biology.organism_classification Molecular biology Complementation Biochemistry Genes Mutation |
| Zdroj: | Europe PubMed Central |
| Popis: | The catabolic L-serine (L-threonine) deaminase of Saccharomyces cerevisiae allows the yeast to grow on media with L-serine or L-threonine as sole nitrogen source. A mutant, cha1 (catabolism of hydroxyamino acids), lacking this enzyme activity has been isolated. We have cloned the CHA1 gene by complementation of a cha1 mutation. Northern analysis showed that CHA1 mRNA has a size of about 1200 ribonucleotides. CHA1 is probably the structural gene for the enzyme; it is an abundant RNA in cells grown with serine and threonine as nitrogen source, whereas it is not detected when cells are grown on ammonium or proline, i.e., the transcription of the CHA1 gene is induced by serine or threonine. Under induced growth conditions haploid ilv1 CHA1 strains do not require isoleucine, i.e., the catabolic deaminase is able to substitute for the biosynthetic threnonine deaminase encoded by the ILV1 gene. We have identified a nuclear, recessive mutation, sil1, that suppresses ilv1 mutations by increased transcription of the CHA1 gene under growth conditions leading to partial induction. The sil1 mutation could exert its effect by increasing the effective pools of the hydroxyamino acids. Alternatively SIL1 may encode a negatively acting regulatory protein for CHA1. |
| Databáze: | OpenAIRE |
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