Promoter selectivity ofEscherichia coliRNA polymerase: omega factor is responsible for the ppGpp sensitivity
نویسندگان
چکیده
منابع مشابه
Promoter selectivity of Escherichia coli RNA polymerase: omega factor is responsible for the ppGpp sensitivity.
Transcription in vitro of stringently controlled Escherichia coli genes by purified RNA polymerase holoenzyme is inhibited by guanosine tetraphosphate (ppGpp). In order to examine possible role of omega factor in this ppGpp sensitivity, RNA polymerases with or without the omega factor were reconstituted and tested for their ppGpp sensitivity using an in vitro mixed transcription system. RNA pol...
متن کاملPromoter-specific control of E. coli RNA polymerase by ppGpp and a general transcription factor.
The stringent response of Escherichia coli reflects a global influence of the nucleotide ppGpp on gene expression in response to nutrient starvation. For critical elements of the response, the target of ppGpp is RNA polymerase, which can be either repressed or activated in a promoter-dependent way. A small protein, DksA, which binds in the secondary channel of RNA polymerase, possibly along wit...
متن کاملPpGpp regulates the binding of two RNA polymerase molecules to the tyrT promoter.
Bacterial promoters differ in the number of RNA polymerase molecules that bind to form a filterable polymerase-promoter complex. We show that two holoenzyme molecules interact with the tyrT promoter, probably as a dimer. This interaction is inhibited by ppGpp. By contrast a single holoenzyme monomer suffices for complex formation at the lacUV5 promoter. We propose that In vivo promoter selectio...
متن کاملE coli RNA polymerase-rRNA promoter interaction and the effect of ppGpp.
The interaction between RNA polymerase and the E coli r (ibosomal) RNA promoters of the rrnX and rrnE operon was studied with the filter-binding technique. Quantitative differences were observed between the rrnX and rrnE promoters: stable rrnX promoter complexes are formed faster, and are less sensitive towards heparin and salt than stable rrnE promoter complexes. The effect of ppGpp, the speci...
متن کاملThe magic spot: a ppGpp binding site on E. coli RNA polymerase responsible for regulation of transcription initiation.
The global regulatory nucleotide ppGpp ("magic spot") regulates transcription from a large subset of Escherichia coli promoters, illustrating how small molecules can control gene expression promoter-specifically by interacting with RNA polymerase (RNAP) without binding to DNA. However, ppGpp's target site on RNAP, and therefore its mechanism of action, has remained unclear. We report here a bin...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Nucleic Acids Research
سال: 1989
ISSN: 0305-1048,1362-4962
DOI: 10.1093/nar/17.21.8755