Binding of Escherichia coli RNA polymerase to a promoter carrying mutations that stop transcription initiation.
The gal P2 promoter can be inactivated by point mutations located in the -10 hexamer sequence or immediately upstream from it. Mutations at either site reduce expression in vivo and prevent the formation, in vitro, of tight complexes with RNA polymerase that give a strong footprint and can initiate transcription. However, with a mutation upstream from the -10 region, RNA polymerase could still make a specific contact with gal promoter DNA as judged by interference with cleavage by restriction enzyme SfaNI at a site within the promoter. In contrast, with a mutation in the -10 hexamer sequence, RNA polymerase could not make this contact and does not interfere with restriction by SfaNI.
Johnston
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F
University of Birmingham, Department of Biochemistry, England.
Ponnambalam
S
S
Busby
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S
D001483:Base Sequence; D004269:DNA, Bacterial; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology*; D009154:Mutation; D011401:Promoter Regions, Genetic; D014158:Transcription, Genetic
D004269:DNA, Bacterial; D012321:DNA-Directed RNA Polymerases