Limited digestion of RNA polymerase from Escherichia coli by trypsin (effect of rifamycin and DNA on the integrity of sigma subunit)

1982 ◽  
Vol 106 (2) ◽  
pp. 663-670 ◽  
Author(s):  
Mukti H. Sarma ◽  
Roswitha G. Dorr ◽  
Ramaswamy H. Sarma
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Limited Digestion ◽  
Sigma Subunit

scholarly journals The sigma subunit conserved region 3 is part of “5'-face” of active center of Escherichia coli RNA polymerase.

1994 ◽  
Vol 269 (33) ◽  
pp. 20826-20828 ◽  
Author(s):  
K. Severinov ◽  
D. Fenyö ◽  
E. Severinova ◽  
A. Mustaev ◽  
B.T. Chait ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Active Center ◽  
Conserved Region ◽  
Sigma Subunit

scholarly journals Effects of distortions by A-tracts of promoter B-DNA spacer region on the kinetics of open complex formation by Escherichia coli RNA polymerase.

2003 ◽  
Vol 50 (4) ◽  
pp. 909-920 ◽  
Author(s):  
Iwona K Kolasa ◽  
Tomasz Łoziński ◽  
Kazimierz L Wierzchowski
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Transcription Initiation ◽  
Specific Interaction ◽  
Structural Data ◽  
Structural Morphology ◽  
Promoter Dna ◽  
Sigma Subunit ◽  
Kinetics Of

A-tracts in DNA due to their structural morphology distinctly different from the canonical B-DNA form play an important role in specific recognition of bacterial upstream promoter elements by the carboxyl terminal domain of RNA polymerase alpha subunit and, in turn, in the process of transcription initiation. They are only rarely found in the spacer promoter regions separating the -35 and -10 recognition hexamers. At present, the nature of the protein-DNA contacts formed between RNA polymerase and promoter DNA in transcription initiation can only be inferred from low resolution structural data and mutational and crosslinking experiments. To probe these contacts further, we constructed derivatives of a model Pa promoter bearing in the spacer region one or two An (n = 5 or 6) tracts, in phase with the DNA helical repeat, and studied the effects of thereby induced perturbation of promoter DNA structure on the kinetics of open complex (RPo) formation in vitro by Escherichia coli RNA polymerase. We found that the overall second-order rate constant ka of RPo formation, relative to that at the control promoter, was strongly reduced by one to two orders of magnitude only when the A-tracts were located in the nontemplate strand. A particularly strong 30-fold down effect on ka was exerted by nontemplate A-tracts in the -10 extended promoter region, where an involvement of nontemplate TG (-14, -15) sequence in a specific interaction with region 3 of sigma-subunit is postulated. A-tracts in the latter location caused also 3-fold slower isomerization of the first closed transcription complex into the intermediate one that precedes formation of RPo, and led to two-fold faster dissociation of the latter. All these findings are discussed in relation to recent structural and kinetic models of RPo formation.

Overexpression and purification of the sigma subunit of Escherichia coli RNA polymerase

Gene ◽  
1983 ◽  
Vol 26 (2-3) ◽  
pp. 109-118 ◽  
Author(s):  
Michael Gribskov ◽  
Richard R. Burgess
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Sigma Subunit

scholarly journals Sigma subunit of Escherichia coli RNA polymerase affects the function of lambda N gene.

1979 ◽  
Vol 76 (9) ◽  
pp. 4593-4597 ◽  
Author(s):  
Y. Nakamura ◽  
T. Kurihara ◽  
H. Saito ◽  
H. Uchida
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
N Gene ◽  
Sigma Subunit

scholarly journals Translational Regulation of the Escherichia coli Stress Factor RpoS: a Role for SsrA and Lon

2007 ◽  
Vol 189 (13) ◽  
pp. 4872-4879 ◽  
Author(s):  
Caroline Ranquet ◽  
Susan Gottesman
Keyword(s):  
Escherichia Coli ◽  
Low Temperature ◽  
Rna Polymerase ◽  
Transcription Initiation ◽  
Translational Regulation ◽  
Regulatory Rna ◽  
Gene Encoding ◽  
Ribosome Stalling ◽  
High Level ◽  
Sigma Subunit

ABSTRACT Escherichia coli cell viability during starvation is strongly dependent on the expression of the rpoS gene, encoding the RpoS sigma subunit of RNA polymerase. RpoS abundance has been reported to be regulated at many levels, including transcription initiation, translation, and protein stability. The regulatory RNA SsrA (or tmRNA) has both tRNA and mRNA activities, relieving ribosome stalling and cotranslationally tagging proteins. We report here that SsrA is needed for the correct high-level translation of RpoS. The ATP-dependent protease Lon was also found to negatively affect RpoS translation, but only at low temperature. We suggest that SsrA may indirectly improve RpoS translation by limiting ribosome stalling and depletion of some component of the translation machinery.

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