6S RNA – an ancient regulator of bacterial RNA polymerase rediscovered

2005 ◽  
Vol 386 (12) ◽  
pp. 1273-1277 ◽  
Author(s):  
Dagmar K. Willkomm ◽  
Roland K. Hartmann
Keyword(s):  
Rna Polymerase ◽  
Dependent Manner ◽  
Bacterial Rna ◽  
Promoter Complex ◽  
6S Rna ◽  
Σ Factor ◽  
Central Bulge ◽  
The Common ◽  
Non Coding Rnas ◽  
Year 2000

AbstractThe bacterial riboregulator 6S RNA was one of the first non-coding RNAs to be discovered in the late 1960s, but its cellular role remained enigmatic until the year 2000. 6S RNA, only recognized to be ubiquitous among bacteria in 2005, binds to RNA polymerase in a σ factor-dependent manner to repress transcription from a subgroup of promoters. The common feature of a double-stranded rod with a central bulge has led to the proposal that 6S RNA may mimic an open promoter complex.

scholarly journals The extent of B-form structure in a 6S RNA variant that mimics DNA to bind to the Escherichia coli RNA Polymerase

2018 ◽  
Author(s):  
Nilesh K. Banavali
Keyword(s):  
Escherichia Coli ◽  
Nucleic Acid ◽  
Structural Analysis ◽  
Rna Polymerase ◽  
Rna Structure ◽  
Recent Article ◽  
Single Strand ◽  
Bacterial Rna ◽  
6S Rna

AbstractIn a recent article by Darst and coworkers, it was found that a non-coding 6S RNA variant regulates a bacterial RNA polymerase by mimicking B-Form DNA, and a few different nucleic acid duplex parameters were analyzed to understand the extent of B-form RNA structure. In this manuscript, a different structural analysis based on conformational distance from canonical A-form and B-form single-strand structures is presented. This analysis addresses the occurrence and extent of both local and global B-form structure in the published 6S RNA variant model.

scholarly journals Bacterial RNA polymerase can retain σ70 throughout transcription

2016 ◽  
Vol 113 (3) ◽  
pp. 602-607 ◽  
Author(s):  
Timothy T. Harden ◽  
Christopher D. Wells ◽  
Larry J. Friedman ◽  
Robert Landick ◽  
Ann Hochschild ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Single Molecule ◽  
Transcription Initiation ◽  
Messenger Rna ◽  
Initiation Factors ◽  
Bacterial Rna ◽  
Direct Measurements ◽  
Promoter Recognition ◽  
Σ Factor ◽  
Transcript Elongation

Production of a messenger RNA proceeds through sequential stages of transcription initiation and transcript elongation and termination. During each of these stages, RNA polymerase (RNAP) function is regulated by RNAP-associated protein factors. In bacteria, RNAP-associated σ factors are strictly required for promoter recognition and have historically been regarded as dedicated initiation factors. However, the primary σ factor in Escherichia coli, σ70, can remain associated with RNAP during the transition from initiation to elongation, influencing events that occur after initiation. Quantitative studies on the extent of σ70 retention have been limited to complexes halted during early elongation. Here, we used multiwavelength single-molecule fluorescence-colocalization microscopy to observe the σ70–RNAP complex during initiation from the λ PR′ promoter and throughout the elongation of a long (>2,000-nt) transcript. Our results provide direct measurements of the fraction of actively transcribing complexes with bound σ70 and the kinetics of σ70 release from actively transcribing complexes. σ70 release from mature elongation complexes was slow (0.0038 s−1); a substantial subpopulation of elongation complexes retained σ70 throughout transcript elongation, and this fraction depended on the sequence of the initially transcribed region. We also show that elongation complexes containing σ70 manifest enhanced recognition of a promoter-like pause element positioned hundreds of nucleotides downstream of the promoter. Together, the results provide a quantitative framework for understanding the postinitiation roles of σ70 during transcription.

scholarly journals Structural basis for transcription activation by Crl through tethering of σS and RNA polymerase

2019 ◽  
Vol 116 (38) ◽  
pp. 18923-18927 ◽  
Author(s):  
Alexis Jaramillo Cartagena ◽  
Amy B. Banta ◽  
Nikhil Sathyan ◽  
Wilma Ross ◽  
Richard L. Gourse ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Transcription Initiation ◽  
Structural Basis ◽  
Functional Importance ◽  
Structural Element ◽  
Cryo Electron Microscopy ◽  
Promoter Complex ◽  
Σ Factor ◽  
Promoter Dna ◽  
Transcription Activators

In bacteria, a primary σ-factor associates with the core RNA polymerase (RNAP) to control most transcription initiation, while alternative σ-factors are used to coordinate expression of additional regulons in response to environmental conditions. Many alternative σ-factors are negatively regulated by anti–σ-factors. In Escherichia coli, Salmonella enterica, and many other γ-proteobacteria, the transcription factor Crl positively regulates the alternative σS-regulon by promoting the association of σS with RNAP without interacting with promoter DNA. The molecular mechanism for Crl activity is unknown. Here, we determined a single-particle cryo-electron microscopy structure of Crl-σS-RNAP in an open promoter complex with a σS-regulon promoter. In addition to previously predicted interactions between Crl and domain 2 of σS (σS2), the structure, along with p-benzoylphenylalanine cross-linking, reveals that Crl interacts with a structural element of the RNAP β′-subunit that we call the β′-clamp-toe (β′CT). Deletion of the β′CT decreases activation by Crl without affecting basal transcription, highlighting the functional importance of the Crl-β′CT interaction. We conclude that Crl activates σS-dependent transcription in part through stabilizing σS-RNAP by tethering σS2 and the β′CT. We propose that Crl, and other transcription activators that may use similar mechanisms, be designated σ-activators.

scholarly journals Dual role of the σ factor in primer RNA synthesis by bacterial RNA polymerase

FEBS Letters ◽  
2018 ◽  
Vol 593 (3) ◽  
pp. 361-368
Author(s):  
Daria Esyunina ◽  
Danil Pupov ◽  
Andrey Kulbachinskiy
Keyword(s):  
Rna Polymerase ◽  
Rna Synthesis ◽  
Dual Role ◽  
Bacterial Rna ◽  
Σ Factor ◽  
Primer Rna

scholarly journals Mechanism of Eukaryotic RNA Polymerase III Transcription Termination

Science ◽  
2013 ◽  
Vol 340 (6140) ◽  
pp. 1577-1580 ◽  
Author(s):  
Soren Nielsen ◽  
Yulia Yuzenkova ◽  
Nikolay Zenkin
Keyword(s):  
Rna Polymerase ◽  
Rna Secondary Structure ◽  
Common Ancestor ◽  
Rna Polymerase Iii ◽  
Rna Molecules ◽  
Polymerase Iii ◽  
Bacterial Rna ◽  
Catalytic Inactivation ◽  
The Common ◽  
Pol Iii

Gene expression in organisms involves many factors and is tightly controlled. Although much is known about the initial phase of transcription by RNA polymerase III (Pol III), the enzyme that synthesizes the majority of RNA molecules in eukaryotic cells, termination is poorly understood. Here, we show that the extensive structure of Pol III–synthesized transcripts dictates the release of elongation complexes at the end of genes. The poly-T termination signal, which does not cause termination in itself, causes catalytic inactivation and backtracking of Pol III, thus committing the enzyme to termination and transporting it to the nearest RNA secondary structure, which facilitates Pol III release. Similarity between termination mechanisms of Pol III and bacterial RNA polymerase suggests that hairpin-dependent termination may date back to the common ancestor of multisubunit RNA polymerases.

scholarly journals Regulation of bacterial RNA polymerase σ factor activity: a structural perspective

2008 ◽  
Vol 11 (2) ◽  
pp. 121-127 ◽  
Author(s):  
Elizabeth A Campbell ◽  
Lars F Westblade ◽  
Seth A Darst
Keyword(s):  
Rna Polymerase ◽  
Factor Activity ◽  
Bacterial Rna ◽  
Σ Factor ◽  
Structural Perspective

scholarly journals Author response: Structure of a bacterial RNA polymerase holoenzyme open promoter complex

2015 ◽  
Author(s):  
Brian Bae ◽  
Andrey Feklistov ◽  
Agnieszka Lass-Napiorkowska ◽  
Robert Landick ◽  
Seth A Darst
Keyword(s):  
Rna Polymerase ◽  
Author Response ◽  
Bacterial Rna ◽  
Promoter Complex ◽  
Rna Polymerase Holoenzyme

scholarly journals Structure of a bacterial RNA polymerase holoenzyme open promoter complex

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Brian Bae ◽  
Andrey Feklistov ◽  
Agnieszka Lass-Napiorkowska ◽  
Robert Landick ◽  
Seth A Darst
Keyword(s):  
Rna Polymerase ◽  
Bubble Formation ◽  
Thermus Aquaticus ◽  
Transcription Bubble ◽  
Template Strand ◽  
Bacterial Rna ◽  
Promoter Complex ◽  
Primary Means ◽  
Promoter Dna ◽  
Biochemical Analyses

Initiation of transcription is a primary means for controlling gene expression. In bacteria, the RNA polymerase (RNAP) holoenzyme binds and unwinds promoter DNA, forming the transcription bubble of the open promoter complex (RPo). We have determined crystal structures, refined to 4.14 Å-resolution, of RPo containing Thermus aquaticus RNAP holoenzyme and promoter DNA that includes the full transcription bubble. The structures, combined with biochemical analyses, reveal key features supporting the formation and maintenance of the double-strand/single-strand DNA junction at the upstream edge of the −10 element where bubble formation initiates. The results also reveal RNAP interactions with duplex DNA just upstream of the −10 element and potential protein/DNA interactions that direct the DNA template strand into the RNAP active site. Addition of an RNA primer to yield a 4 base-pair post-translocated RNA:DNA hybrid mimics an initially transcribing complex at the point where steric clash initiates abortive initiation and σA dissociation.

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