Identification and characterization of the activation domain of Ifh1, an activator of model TATA-less genes.
In yeast, TATA box-binding protein TBP can be delivered to protein-coding genes by direct interactions with two different coactivators: TFIID, which delivers TBP preferentially to TATA-less promoters, and SAGA, which strongly favors TATA box-containing promoters. Transcriptional activators of SAGA-dependant genes are characterized by prototypic acidic activation domains (ADs) that efficiently recruit SAGA, but not TFIID, to UAS elements even in the absence of a core promoter. In contrast to the well-studied acidic activation domains, little is known about the activation domains of activators of TFIID-dependent genes, even though these genes constitute more than 80% of eukaryotic protein-coding genes. The paradigm for TATA-less genes are the ribosomal protein genes (RPGs). Here we have identified the AD of the RPG activator Ifh1p and demonstrate that a minimal Ifh1 AD represents a new class of AD that significantly differs from acidic ADs in amino acid signature, relative coactivator affinities, and core promoter selectivity.
Zhong
Peipei
P
School of Biomedical Sciences, University of Ulster, Coleraine, UK.
Melcher
Karsten
K
D000595:Amino Acid Sequence; D015966:Gene Expression Regulation, Fungal; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D016385:TATA Box; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation
C094046:IFH1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators