In vitro regulation of a SIN3-dependent DNA-binding activity by stimulatory and inhibitory factors.
The yeast SIN3 gene (also known as SDII, is a known negative regulator of the yeast HO gene. A DNA-binding activity, called SDP1, which binds to the HO promoter, is absent in extracts prepared from sin3 mutants and has been proposed to function as a repressor. We show that SIN3 does not encode SDP1 and that SDP1 DNA-binding activity is modulated in vitro by two factors, an inhibitory factor, I-SDP1, and a stimulatory factor, S-SDP1. I-SDP1 acts as an in vitro inhibitor of the SDP1 DNA-binding activity. Restoration of the DNA-binding activity is achieved by inclusion of a stimulatory factor, S-SDP1, which copurifies with the SIN3 protein. SDP1 DNA-binding activity was restored by treating a protein fraction containing SDP1 and I-SDP1 with the dissociating agent formamide.
Wang
H
H
Department of Cellular, Viral, and Molecular Biology, University of Utah School of Medicine, Salt Lake City 84132.
Stillman
D J
DJ
D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000235:genetics*; D005559:Formamides / Q000494:pharmacology; D005800:Genes, Fungal; D005809:Genes, Regulator; D007700:Kinetics; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D011401:Promoter Regions, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism
D004268:DNA-Binding Proteins; D005559:Formamides; D015345:Oligonucleotide Probes; C031066:formamide