A large internal deletion converts yeast LEU3 to a constitutive transcriptional activator.
LEU3 of Saccharomyces cerevisiae encodes an 886-amino-acid polypeptide that activates transcription of at least five genes by binding to an upstream decanucleotide sequence. This activation is dependent on the inducer alpha-isopropylmalate, the synthesis of which is repressed by leucine. We created a 285-amino-acid LEU3 derivative by removing a large block of internal sequences, including a dense cluster of acidic residues. This deletion protein bound to the decanucleotide sequence in vitro and activated gene expression in vivo. In contrast to wild-type LEU3, the truncated LEU3 protein was an effective transcriptional activator when alpha-isopropylmalate synthesis was repressed by leucine.
Friden
P
P
Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.
Reynolds
C
C
Schimmel
P
P
D002872:Chromosome Deletion; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D005800:Genes, Fungal; D005809:Genes, Regulator; D007930:Leucine / Q000235:genetics; D008293:Malates / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
D004271:DNA, Fungal; D008293:Malates; C005906:alpha-isopropylmalate; D007930:Leucine