title: The DNA-binding domain of the yeast Spt10p activator includes a zinc finger that is homologous to foamy virus integrase.
abstract: The yeast SPT10 gene encodes a putative histone acetyltransferase that binds specifically to pairs of upstream activating sequence (UAS) elements found only in the histone gene promoters. Here, we demonstrate that the DNA-binding domain of Spt10p is located between residues 283 and 396 and includes a His(2)-Cys(2) zinc finger. The binding of Spt10p to the histone UAS is zinc-dependent and is disabled by a zinc finger mutation (C388S). The isolated DNA-binding domain binds to single histone UAS elements with high affinity. In contrast, full-length Spt10p binds with high affinity only to pairs of UAS elements with very strong positive cooperativity and is unable to bind to a single UAS element. This implies the presence of a "blocking" domain in full-length Spt10p, which forces it to search for a pair of UAS elements. Chromatin immunoprecipitation experiments indicate that, unlike wild-type Spt10p, the C388S protein does not bind to the promoter of the gene encoding histone H2A (HTA1) in vivo. The C388S mutant has a phenotype similar to that of the spt10Delta mutant: poor growth and global aberrations in gene expression. Thus, the C388S mutation disables the DNA-binding function of Spt10p in vitro and in vivo. The zinc finger of Spt10p is homologous to that of foamy virus integrase, perhaps suggesting that this integrase is also a sequence-specific DNA-binding protein.
authors.affiliation: Laboratory of Molecular Growth Regulation, NICHD/National Institutes of Health, 6 Center Drive, Bethesda, MD 20892-2426, USA.
authors.forename: Geetu
authors.initials: G
authors.lastname: Mendiratta
authors.forename: Peter R
authors.initials: PR
authors.lastname: Eriksson
authors.forename: Chang-Hui
authors.initials: CH
authors.lastname: Shen
authors.forename: David J
authors.initials: DJ
authors.lastname: Clark
mesh_terms: D000595:Amino Acid Sequence; D047369:Chromatin Immunoprecipitation; D004247:DNA / Q000737:chemistry*; D004268:DNA-Binding Proteins / Q000737:chemistry; D015966:Gene Expression Regulation, Fungal; D051548:Histone Acetyltransferases; D006657:Histones / Q000737:chemistry; D019426:Integrases / Q000737:chemistry*; D008969:Molecular Sequence Data; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D016092:Spumavirus / Q000201:enzymology*; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics*; D014158:Transcription, Genetic; D015032:Zinc / Q000737:chemistry; D016335:Zinc Fingers
chemical_list: D004268:DNA-Binding Proteins; D006657:Histones; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D004247:DNA; D051548:Histone Acetyltransferases; C086444:SPT10 protein, S cerevisiae; D019426:Integrases; D015032:Zinc