The yeast TRP5 gene is part of the amino acid biosynthesis pathway.
Understanding gene regulation is crucial for metabolic engineering and synthetic biology.
Purpose of the Study:
To investigate the promoter function and regulatory elements of the yeast TRP5 gene.
To identify specific DNA sequences responsible for the general control regulation of TRP5.
Main Methods:
Construction of a TRP5-lacZ translational fusion in yeast.
Deletion analysis of the 5'-flanking region of the TRP5 gene.
Assay of beta-galactosidase activity to determine promoter function and regulation.
Main Results:
The TRP5-lacZ fusion demonstrated 4-5 fold derepression under lysine limitation, confirming regulation by general control.
Deletion mapping localized the TRP5 promoter to within 188 base pairs of the transcription start site.
Two separable promoter subregions, approximately -188 to -114 and -91 to -29, were identified, with the TATA box in the downstream region. Regulatory elements essential for general control overlap these regions, each containing a TGACT repeat.
Conclusions:
The TRP5 gene promoter contains distinct regulatory elements essential for general control.
The identified promoter regions and TGACT repeats provide insights into the molecular mechanisms of amino acid biosynthesis regulation in yeast.