In vitro binding of the two-finger repressor CreA to several consensus and non-consensus sites at the ipnA upstream region is context dependent.
The two zinc-fingers of the Aspergillus nidulans repressor CreA recognize the consensus hexanucleotide 5'-SYGGRG-3'. We have determined all the CreA binding sites in a approximately 2 kb region upstream the ipnA gene. Our analysis shows that (i) CreA binds to certain consensus sites in a context-dependent manner; (ii) five non-consensus 6-bp sequences are also recognized by CreA; this non-canonical binding correlates with the presence of a second, neighbouring CreA binding site, suggesting that recognition of two linked sites stabilizes CreA binding. Our results suggest that the binding possibilities of CreA might be more complex than originally envisaged.
Espeso
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EA
Centro de Investigaciones Biológicas del CSIC, Madrid, Spain.
Peñalva
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MA
D001233:Aspergillus nidulans / Q000235:genetics / Q000378:metabolism*; D001482:Base Composition; D001483:Base Sequence; D001665:Binding Sites; D016384:Consensus Sequence; D004271:DNA, Fungal / Q000737:chemistry / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism*; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*; D016335:Zinc Fingers
D004271:DNA, Fungal; D005656:Fungal Proteins; D009838:Oligodeoxyribonucleotides; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; C071237:CreA protein, Aspergillus nidulans