Amber dnaG mutation exerting a polar effect on the synthesis of RNA polymerase sigma factor in Escherichia coli

1984 ◽  
Vol 196 (1) ◽  
pp. 179-182 ◽  
Author(s):  
Yoshikazu Nakamura
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Sigma Factor ◽  
Polar Effect

scholarly journals Substitution of a Highly Conserved Histidine in the Escherichia coli Heat Shock Transcription Factor, σ32, Affects Promoter Utilization In Vitro and Leads to Overexpression of the Biofilm-Associated Flu Protein In Vivo

2007 ◽  
Vol 189 (23) ◽  
pp. 8430-8436 ◽  
Author(s):  
Olga V. Kourennaia ◽  
Pieter L. deHaseth
Keyword(s):  
Escherichia Coli ◽  
Heat Shock ◽  
Rna Polymerase ◽  
Sigma Factor ◽  
Stable Complex ◽  
Tryptophan Residue ◽  
Specific Sequence ◽  
Bacterial Rna

ABSTRACT The heat shock sigma factor (σ32 in Escherichia coli) directs the bacterial RNA polymerase to promoters of a specific sequence to form a stable complex, competent to initiate transcription of genes whose products mitigate the effects of exposure of the cell to high temperatures. The histidine at position 107 of σ32 is at the homologous position of a tryptophan residue at position 433 of the main sigma factor of E. coli, σ70. This tryptophan is essential for the strand separation step leading to the formation of the initiation-competent RNA polymerase-promoter complex. The heat shock sigma factors of all gammaproteobacteria sequenced have a histidine at this position, while in the alpha- and deltaproteobacteria, it is a tryptophan. In vitro the alanine-for-histidine substitution at position 107 (H107A) destabilizes complexes between the GroE promoter and RNA polymerase containing σ32, implying that H107 plays a role in formation or maintenance of the strand-separated complex. In vivo, the H107A substitution in σ32 impedes recovery from heat shock (exposure to 42°C), and it also leads to overexpression at lower temperatures (30°C) of the Flu protein, which is associated with biofilm formation.

scholarly journals Interaction of sigma factor σN with Escherichia coli RNA polymerase core enzyme

2000 ◽  
Vol 352 (2) ◽  
pp. 539 ◽  
Author(s):  
David J. SCOTT ◽  
Anna L. FERGUSON ◽  
Maria-Trinidad GALLEGOS ◽  
Melinda PITT ◽  
Martin BUCK ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Sigma Factor ◽  
Core Enzyme

scholarly journals Influence of DNA Template Choice on Transcription and Inhibition of Escherichia coli RNA Polymerase

2012 ◽  
Vol 56 (8) ◽  
pp. 4536-4539 ◽  
Author(s):  
Joerg Haupenthal ◽  
Kristina Hüsecken ◽  
Matthias Negri ◽  
Christine K. Maurer ◽  
Rolf W. Hartmann
Keyword(s):  
Escherichia Coli ◽  
Drug Discovery ◽  
Rna Polymerase ◽  
Sigma Factor ◽  
Inhibitory Potency ◽  
Experimental Conditions ◽  
Early Stages ◽  
Bacterial Rna ◽  
Transcription Efficiency ◽  
Dna Template

ABSTRACTIn recent decades, quantitative transcription assays using bacterial RNA polymerase (RNAP) have been performed under widely diverse experimental conditions. We demonstrate that the template choice can influence the inhibitory potency of RNAP inhibitors. Furthermore, we illustrate that the sigma factor (σ70) surprisingly increases the transcription efficiency of templates with nonphysiological nonprokaryotic promoters. Our results might be a useful guideline in the early stages of using RNAP for drug discovery.

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