title: Sequence-directed bends of DNA helix axis at the upstream activation sites of alpha-cell-specific genes in yeast.
abstract: The MF alpha 1 gene of Saccharomyces cerevisiae, a major structural gene for mating pheromone alpha factor, is an alpha-cell-specific gene whose expression is regulated by the mating-type locus, MAT. Two upstream activation sites (UASMF alpha 1s), which are binding sites for an activator protein, MAT alpha 1, mediate alpha-cell-specific expression of this gene. We show here that DNA fragments containing the UASMF alpha 1 region exhibited anomalous slow electrophoretic mobilities on gels at lower temperature, but not at higher temperature, that is characteristic of bent DNA. We confirmed the sequence-directed bend at the UASMF alpha 1 region by employing a circular permutation analysis and a DNA cyclization assay. Deletion analyses revealed the existence of two bends in this region, each of which overlaps each UASMF alpha 1 element. The two bends were almost in phase; they lie in a nearly same plane with a same direction. We also show the existence of sequence-directed bend at the UAS region of the STE3 gene, another alpha-specific gene in S. cerevisiae. These bent DNAs may be involved in transcriptional regulation of this set of genes.
mesh_terms: D001483:Base Sequence; D004252:DNA Mutational Analysis; D004271:DNA, Fungal / Q000235:genetics*; D005800:Genes, Fungal; D049770:Genes, Mating Type, Fungal; D000072235:Mating Factor; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010455:Peptides / Q000235:genetics*; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D013329:Structure-Activity Relationship
chemical_list: D004271:DNA, Fungal; D010455:Peptides; D000072235:Mating Factor