Region 1.2 of the RNA polymerase sigma subunit controls recognition of the -10 promoter element.
Recognition of the -10 promoter consensus element by region 2 of the bacterial RNA polymerase sigma subunit is a key step in transcription initiation. sigma also functions as an elongation factor, inducing transcription pausing by interacting with transcribed DNA non-template strand sequences that are similar to the -10 element sequence. Here, we show that the region 1.2 of Escherichia coli sigma70, whose function was heretofore unknown, is strictly required for efficient recognition of the non-template strand of -10-like pause-inducing DNA sequence by sigma region 2, and for sigma-dependent promoter-proximal pausing. Recognition of the fork-junction promoter DNA by RNA polymerase holoenzyme also requires sigma region 1.2 and thus resembles the pause-inducing sequence recognition. Our results, together with available structural data, support a model where sigma region 1.2 acts as a core RNA polymerase-dependent allosteric switch that modulates non-template DNA strand recognition by sigma region 2 during transcription initiation and elongation.
Zenkin
Nikolay
N
Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia.
Kulbachinskiy
Andrey
A
Yuzenkova
Yuliya
Y
Mustaev
Arkady
A
Bass
Irina
I
Severinov
Konstantin
K
Brodolin
Konstantin
K
D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D008957:Models, Genetic; D008958:Models, Molecular; D009841:Oligonucleotides; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012808:Sigma Factor / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics / Q000502:physiology*
D009841:Oligonucleotides; D012808:Sigma Factor; C081775:RNA polymerase sigma 70; D012321:DNA-Directed RNA Polymerases