Characterization of a new prokaryotic transcriptional activator and its DNA recognition site.
The expression of the Bacillus subtilis phage phi 29 DNA is controlled by the viral gene 4 product, which is required for the initiation of transcription at the unique late promoter A3. Protein p4 binds specifically to a phi 29 DNA fragment containing the A3 promoter. DNase I footprinting analysis has shown that the DNA binding region for protein p4 is located between nucleotides -50 and -100 relative to the transcription start site. Methylation interference assays suggest that two eight base-pair long inverted repeats located within this binding region are the protein p4 recognition sequence. These results, together with the fact that the protein p4-dependent in vitro transcription requires the B. subtilis sigma 43-RNA polymerase, indicate that protein p4 is a transcriptional activator. The protein p4 DNA recognition region is statically bent as suggested by gel retardation and chemical cleavage assays. A model of protein p4 binding to its DNA target site is proposed.
Barthelemy
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I
Centro de Biología Molecular (CSIC-UAM), Universidad Autónoma, Canto Blanco, Madrid, Spain.
Salas
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M
D001412:Bacillus subtilis / Q000201:enzymology; D001435:Bacteriophages / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D004279:DNA, Viral / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000235:genetics*
D004279:DNA, Viral; D004268:DNA-Binding Proteins; D014764:Viral Proteins; D012321:DNA-Directed RNA Polymerases