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Regulation of transcription elongation and termination.

Washburn RS, Gottesman ME - Biomolecules (2015)

Bottom Line: We discuss why transcription elongation complexes pause at certain template sites and how auxiliary host and phage transcription factors affect elongation and termination.The connection between translation and transcription elongation is described.Finally we present an overview indicating where progress has been made and where it has not.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA. rw378@cumc.columbia.edu.

ABSTRACT
This article will review our current understanding of transcription elongation and termination in E. coli. We discuss why transcription elongation complexes pause at certain template sites and how auxiliary host and phage transcription factors affect elongation and termination. The connection between translation and transcription elongation is described. Finally we present an overview indicating where progress has been made and where it has not.

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The sequence of Nun and N proteins. Blue—residues of ARM motif. Red—Residues with arrest-deficient phenotype. Underlined—other mutations affecting Nun activity.
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biomolecules-05-01063-f003: The sequence of Nun and N proteins. Blue—residues of ARM motif. Red—Residues with arrest-deficient phenotype. Underlined—other mutations affecting Nun activity.

Mentions: TEC paused by nucleotide deprivation in vitro is a substrate for subsequent Nun arrest, although the site of arrest differs depending on the location of the pause [79,80]. Mutational analysis of the Nun C-terminus indicates that a penultimate aromatic residue (W108) is required for Nun arrest (Figure 3, top). The Nun C-terminus crosslinks to template DNA about 9 bp promoter-distal to the RNAP active center. This is compatible with the idea that Nun arrests transcription by anchoring TEC to the DNA template, perhaps via intercalation of the W108 residue. Two neighboring basic Nun C-terminal residues, K106 and K107 (Figure 3, top) are required for efficient arrest. They are thought to aid Nun binding to the negatively-charged DNA template. The Nun mechanism of action was tested on defined TEC scaffolds consisting of DNA template and non-template strands and RNA complementary to the template strand. These TECs differed in the length and the sequences of the RNA primer. Importantly, the scaffolds included no λ DNA or RNA sequences. Nun arrested all TECs tested that carried an RNA:DNA hybrid 9 bp or longer. For each TEC, Nun-mediated arrest occurred at a specific site, corresponding to an intrinsic pause site [77,81,82]. Nun-arrested TEC were found in either the pretranslocated or the posttranslocated state. Nun arrests transcription elongation by preventing movement of TEC from one register to the other [79,80].


Regulation of transcription elongation and termination.

Washburn RS, Gottesman ME - Biomolecules (2015)

The sequence of Nun and N proteins. Blue—residues of ARM motif. Red—Residues with arrest-deficient phenotype. Underlined—other mutations affecting Nun activity.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4496710&req=5

biomolecules-05-01063-f003: The sequence of Nun and N proteins. Blue—residues of ARM motif. Red—Residues with arrest-deficient phenotype. Underlined—other mutations affecting Nun activity.
Mentions: TEC paused by nucleotide deprivation in vitro is a substrate for subsequent Nun arrest, although the site of arrest differs depending on the location of the pause [79,80]. Mutational analysis of the Nun C-terminus indicates that a penultimate aromatic residue (W108) is required for Nun arrest (Figure 3, top). The Nun C-terminus crosslinks to template DNA about 9 bp promoter-distal to the RNAP active center. This is compatible with the idea that Nun arrests transcription by anchoring TEC to the DNA template, perhaps via intercalation of the W108 residue. Two neighboring basic Nun C-terminal residues, K106 and K107 (Figure 3, top) are required for efficient arrest. They are thought to aid Nun binding to the negatively-charged DNA template. The Nun mechanism of action was tested on defined TEC scaffolds consisting of DNA template and non-template strands and RNA complementary to the template strand. These TECs differed in the length and the sequences of the RNA primer. Importantly, the scaffolds included no λ DNA or RNA sequences. Nun arrested all TECs tested that carried an RNA:DNA hybrid 9 bp or longer. For each TEC, Nun-mediated arrest occurred at a specific site, corresponding to an intrinsic pause site [77,81,82]. Nun-arrested TEC were found in either the pretranslocated or the posttranslocated state. Nun arrests transcription elongation by preventing movement of TEC from one register to the other [79,80].

Bottom Line: We discuss why transcription elongation complexes pause at certain template sites and how auxiliary host and phage transcription factors affect elongation and termination.The connection between translation and transcription elongation is described.Finally we present an overview indicating where progress has been made and where it has not.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA. rw378@cumc.columbia.edu.

ABSTRACT
This article will review our current understanding of transcription elongation and termination in E. coli. We discuss why transcription elongation complexes pause at certain template sites and how auxiliary host and phage transcription factors affect elongation and termination. The connection between translation and transcription elongation is described. Finally we present an overview indicating where progress has been made and where it has not.

Show MeSH