Cell type-specific chromatin organization of the region that governs directionality of yeast mating type switching.
Switching of mating type in Saccharomyces cerevisiae is directional; MAT alpha cells recombine to transfer information from HMRa while MATa cells switch using the silent cassette at HML alpha. Genetic analysis recently has defined a 700 bp recombination enhancer approximately 29 kb from the left end of chromosome III that is necessary for directionality. The chromatin structure of this region differs strikingly in a- and alpha-cells. Mat alpha2p organizes a 3.7 kb chromatin domain that opposes interaction of trans-acting proteins with the enhancer. In a-cells lacking the alpha2 repressor, two footprinted regions flank an approximately 100 bp section having a unique DNA structure. This structural signature probably reflects interactions of proteins that result in directional mating type switching.
Weiss
K
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Department of Biochemistry and Molecular Biology and Center for Gene Regulation, Penn State University, University Park 16802, USA.
Simpson
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RT
D001483:Base Sequence; D002843:Chromatin / Q000737:chemistry*; D015825:Chromosomes, Fungal; D018983:DNA Footprinting; D003850:Deoxyribonuclease I / Q000378:metabolism; D004742:Enhancer Elements, Genetic / Q000235:genetics; D005800:Genes, Fungal / Q000235:genetics*; D049770:Genes, Mating Type, Fungal; D008836:Micrococcal Nuclease / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009690:Nucleic Acid Conformation; D009707:Nucleosomes / Q000235:genetics; D016133:Polymerase Chain Reaction; D011995:Recombination, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D012441:Saccharomyces cerevisiae / Q000235:genetics*
D002843:Chromatin; D009707:Nucleosomes; D003850:Deoxyribonuclease I; D008836:Micrococcal Nuclease