Publication Date:
2012-09-11
Description:
Transcription-coupled DNA repair uses components of the transcription machinery to identify DNA lesions and initiate their repair. These repair pathways are complex, so their mechanistic features remain poorly understood. Bacterial transcription-coupled repair is initiated when RNA polymerase stalled at a DNA lesion is removed by Mfd, an ATP-dependent DNA translocase. Here we use single-molecule DNA nanomanipulation to observe the dynamic interactions of Escherichia coli Mfd with RNA polymerase elongation complexes stalled by a cyclopyrimidine dimer or by nucleotide starvation. We show that Mfd acts by catalysing two irreversible, ATP-dependent transitions with different structural, kinetic and mechanistic features. Mfd remains bound to the DNA in a long-lived complex that could act as a marker for sites of DNA damage, directing assembly of subsequent DNA repair factors. These results provide a framework for considering the kinetics of transcription-coupled repair in vivo, and open the way to reconstruction of complete DNA repair pathways at single-molecule resolution.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3475728/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3475728/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Howan, Kevin -- Smith, Abigail J -- Westblade, Lars F -- Joly, Nicolas -- Grange, Wilfried -- Zorman, Sylvain -- Darst, Seth A -- Savery, Nigel J -- Strick, Terence R -- BB/I001859/1/Biotechnology and Biological Sciences Research Council/United Kingdom -- BB/I003142/1/Biotechnology and Biological Sciences Research Council/United Kingdom -- GM073829/GM/NIGMS NIH HHS/ -- R01 GM073829/GM/NIGMS NIH HHS/ -- England -- Nature. 2012 Oct 18;490(7420):431-4. doi: 10.1038/nature11430. Epub 2012 Sep 9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cite F-75205 Paris, France.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22960746" target="_blank"〉PubMed〈/a〉
Keywords:
Adenosine Triphosphate/metabolism
;
Bacterial Proteins/*metabolism
;
Biocatalysis
;
DNA Damage
;
*DNA Repair
;
DNA-Directed RNA Polymerases/metabolism
;
Escherichia coli/enzymology/genetics/metabolism
;
Hydrolysis
;
Kinetics
;
Promoter Regions, Genetic/genetics
;
Pyrimidine Dimers/chemistry/metabolism
;
Transcription Elongation, Genetic
;
Transcription Factors/*metabolism
;
Transcription Initiation, Genetic
;
Transcription Termination, Genetic
;
*Transcription, Genetic
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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