Resection and mutagenesis of the acid pH-inducible P2 promoter of the Agrobacterium tumefaciens virG gene.
Transcription of the virG gene initiates from two tandem promoters, designated P1 and P2, that are located 50 nucleotides apart. Transcription of the P2 promoter is induced by extracellular acidity. cis-acting sites required for P2 activity were identified by constructing and assaying a series of 5' and 3' resections and site-directed nucleotide substitutions. Nucleotides between positions -9 and -37 were sufficient for regulated promoter activity. Within this region, nucleotide substitutions at the predicted -10 and -35 regions strongly reduced P2 expression. In addition, alterations in the region between nucleotides -24 and -32 also eliminated or strongly reduced promoter activity. These data suggest that this promoter may be regulated by a positive transcription factor that binds to nucleotide residues in this interval.
Chang
C H
CH
Section of Microbiology, Cornell University, Ithaca, New York 14853, USA.
Winans
S C
SC
D016960:Agrobacterium tumefaciens / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D014157:Transcription Factors; C058483:virG protein, Shigella flexneri