Artículo
Threonine overproduction in yeast strains carrying the HOM3-R2 mutant allele under the control of different inducible promoters
Autor/es | Farfán Espuny, María José
Aparicio, Luis López Calderón, Isabel |
Departamento | Universidad de Sevilla. Departamento de Genética |
Fecha de publicación | 1999 |
Fecha de depósito | 2016-04-21 |
Publicado en |
|
Resumen | The
HOM3
gene of
Saccharomyces cerevisiae
codes for aspartate kinase, which plays a crucial role in the
regulation of the metabolic flux that leads to threonine biosynthesis. With the aim of obtaining yeast ... The HOM3 gene of Saccharomyces cerevisiae codes for aspartate kinase, which plays a crucial role in the regulation of the metabolic flux that leads to threonine biosynthesis. With the aim of obtaining yeast strains able to overproduce threonine in a controlled way, we have placed the HOM3-R2 mutant allele, which causes expression of a feedback-insensitive enzyme, under the control of four distinctive regulatable yeast promoters, namely, P GAL1 ,P CHA1 ,P CYC1-HSE2 , and P GPH1 . The amino acid contents of strains bearing the different con- structs were analyzed both under repression and induction conditions. Although some differences in overall threonine production were found, a maximum of around 400 nmol/mg (dry weight) was observed. Other factors, such as excretion to the medium and activity of the catabolic threonine/serine deaminase, also affect threonine accumulation. Thus, improvement of threonine productivity by yeast cells would probably require manipula- tion of these and other factors. |
Ficheros | Tamaño | Formato | Ver | Descripción |
---|---|---|---|---|
Threonine overproduction.pdf | 104.2Kb | [PDF] | Ver/ | |