Deletion mapping the yeast TRP5 control region.

The yeast gene TRP5 is regulated by the general control system of amino acid biosynthesis. A TRP5-lacZ translational fusion was constructed in order to facilitate assay for TRP5 promoter function and regulation. The chromosomally integrated fusion was derepressed 4-5-fold by lysine limitation. Thus, the TRP5-lacZ fusion is regulated by general control. Deletions were constructed in vitro in the 5'-flanking region of cloned TRP5-lacZ. These deletions localized the promoter region to within 188 base pairs of the transcription start site. Two separable subregions of the promoter were localized by further deletion mapping. The boundaries of the promoter regions are approximately -188 to -114 and -91 to -29. The TATA box is contained within the downstream promoter region. Regulatory regions essential for general control overlap with these promoter elements. Each of two separable regulatory regions contains a copy of the TGACT repeat (Donahue, T. F., Daves, R. S., Lucchini, G., and Fink, G. R. (1983) Cell 32, 89-98) previously implicated in regulation of HIS4 by general control.