Which nucleotides in the "-10" region are crucial to obtain a fully active MalT-dependent promoter?
We have replaced the hexanucleotide corresponding to the "-10" region of malPp, a positively regulated promoter from Escherichia coli, by random nucleotide sequences and isolated 48 different variants that were as active as the wild-type promoter. Analysis of the nucleotide sequence of their "-10" region strongly suggests that the nature of the nucleotide present at three positions plays a crucial role: 46 of the 48 malPp variants contained C or T at position -12, A at position -11 and T at position -7. The nucleotide composition at the three other positions seems to be much more flexible. The features of these "-10" regions are similar to those of the constitutive promoters, but some significant differences are noticeable and will be discussed. In contrast to other positively regulated promoters, none of the various "-10" regions, including the consensus sequence TATAAT, led to a constitutive promoter.
Danot
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Unité de Génétique Moléculaire (CNRS URA 1149), Institut Pasteur, France.
Raibaud
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D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D004269:DNA, Bacterial / Q000032:analysis; D004268:DNA-Binding Proteins; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009838:Oligodeoxyribonucleotides; D009876:Operon; D011401:Promoter Regions, Genetic / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C058976:MalT protein, E coli; D009838:Oligodeoxyribonucleotides; D014157:Transcription Factors