RNA polymerase as a repressor of transcription in the hut(P) region of mutant Klebsiella aerogenes histidine utilization operons.
Mutants of Klebsiella aerogenes able to express the hutUH operon in the absence of positive effectors were isolated and characterized. These mutations improve the hutUH promoter (PUH) by changing the -10 region to match the consensus sequence more closely. These mutations also affect another, oppositely oriented promoter in this region, PC. Although the mutations lie far outside PC, they cause PC to be inactive, apparently because binding of RNA polymerase to the PUH promoter blocks the overlapping PC site. Thus, in the mutants, RNA polymerase bound at the strong (mutant) PUH site effectively repress the PC promoter.
Nieuwkoop
A J
AJ
Department of Biology, University of Michigan, Ann Arbor 48109-1048.
Bender
R A
RA
D002874:Chromosome Mapping; D012321:DNA-Directed RNA Polymerases / Q000502:physiology*; D005786:Gene Expression Regulation; D006639:Histidine / Q000378:metabolism*; D006638:Histidine Ammonia-Lyase / Q000235:genetics; D007709:Klebsiella / Q000235:genetics*; D009154:Mutation; D009876:Operon; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D012097:Repressor Proteins / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology*; D014158:Transcription, Genetic
D012097:Repressor Proteins; D014157:Transcription Factors; D006639:Histidine; D012321:DNA-Directed RNA Polymerases; D006638:Histidine Ammonia-Lyase