Regulation of the TRP4 gene of Saccharomyces cerevisiae at the transcriptional level and functional analysis of its promotor.

The TRP4 gene of Saccharomyces cerevisiae, which encodes anthranilate phosphoribosyl transferase (E.C. 2.4.2.18), is subject to the general control of amino acid biosynthesis. The regulation takes place at the transcriptional level by increasing the amount of initiation and not by changing the stability of mRNA. We have observed a change in the utilization of TRP4 mRNA start sites, depending on whether cells were grown under repressing or derepressing conditions. The function of promoter elements has been tested by deletion analysis with a plasmid-encoded TRP4 gene. A routinely practicable method was used for copy-number calibration of plasmids based on 2 micron DNA. Promoter structures and spacing problems in the TRP4 promoter region are discussed.