The Swi5 zinc-finger and Grf10 homeodomain proteins bind DNA cooperatively at the yeast HO promoter.
SWI5 encodes a zinc-finger protein required for expression of the yeast HO gene. Using Swi5 protein that was purified from a bacterial expression system, we previously isolated a yeast factor that stimulates binding of Swi5 to the HO promoter. N-terminal amino acid sequence analysis identified the Swi5 stimulatory factor as the product of the GRF10 gene, which encodes a yeast homeodomain protein. GRF10, also known as PHO2 and BAS2, is a transcriptional activator of the PHO5 acid phosphatase gene and the HIS4 histidine biosynthesis gene. Grf10 protein purified from a bacterial expression system binds DNA cooperatively with Swi5 in vitro. Analysis of disassociation rates indicates that the Grf10-Swi5-DNA complex has a longer half-life than protein-DNA complexes that contain only Swi5 or Grf10. Finally, we show that HO expression is reduced in yeast strains containing grf10 null mutations and that full expression of a heterologous promoter containing a SWI5-dependent HO upstream activation sequence element requires GRF10.
Brazas
R M
RM
Department of Cellular, Viral, and Molecular Biology, University of Utah Medical Center, Salt Lake City 84132.
Stillman
D J
DJ
D000595:Amino Acid Sequence; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins / Q000737:chemistry*; D003852:Deoxyribonucleoproteins / Q000737:chemistry; D005656:Fungal Proteins / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D005801:Genes, Homeobox; D018398:Homeodomain Proteins; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D016335:Zinc Fingers
D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D003852:Deoxyribonucleoproteins; D005656:Fungal Proteins; D018398:Homeodomain Proteins; D046911:Macromolecular Substances; C051611:PHO2 protein, S cerevisiae; C080218:SWI5 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; D014157:Transcription Factors