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Mechanism of RecQ helicase mechanoenzymatic coupling reveals that the DNA interactions of the ADP-bound enzyme control translocation run terminations
The processing of various DNA structures by RecQ helicases is crucial for genome maintenance in both bacteria and eukaryotes. RecQ helicases perform active destabilization of DNA duplexes, based on tight coupling of their ATPase activity to moderately processive translocation along DNA strands. Here...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Oxford University Press
2015
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4333385/ https://www.ncbi.nlm.nih.gov/pubmed/25539922 http://dx.doi.org/10.1093/nar/gku1333 |
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author | Sarlós, Kata Gyimesi, Máté Kele, Zoltán Kovács, Mihály |
author_facet | Sarlós, Kata Gyimesi, Máté Kele, Zoltán Kovács, Mihály |
author_sort | Sarlós, Kata |
collection | PubMed |
description | The processing of various DNA structures by RecQ helicases is crucial for genome maintenance in both bacteria and eukaryotes. RecQ helicases perform active destabilization of DNA duplexes, based on tight coupling of their ATPase activity to moderately processive translocation along DNA strands. Here, we determined the ATPase kinetic mechanism of E. coli RecQ helicase to reveal how mechanoenzymatic coupling is achieved. We found that the interaction of RecQ with DNA results in a drastic acceleration of the rate-limiting ATP cleavage step, which occurs productively due to subsequent rapid phosphate release. ADP release is not rate-limiting and ADP-bound RecQ molecules make up a small fraction during single-stranded DNA translocation. However, the relatively rapid release of the ADP-bound enzyme from DNA causes the majority of translocation run terminations (i.e. detachment from the DNA track). Thus, the DNA interactions of ADP-bound RecQ helicase, probably dependent on DNA structure, will mainly determine translocation processivity and may control the outcome of DNA processing. Comparison with human Bloom's syndrome (BLM) helicase reveals that similar macroscopic parameters are achieved by markedly different underlying mechanisms of RecQ homologs, suggesting diversity in enzymatic tuning. |
format | Online Article Text |
id | pubmed-4333385 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | Oxford University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-43333852015-03-18 Mechanism of RecQ helicase mechanoenzymatic coupling reveals that the DNA interactions of the ADP-bound enzyme control translocation run terminations Sarlós, Kata Gyimesi, Máté Kele, Zoltán Kovács, Mihály Nucleic Acids Res Nucleic Acid Enzymes The processing of various DNA structures by RecQ helicases is crucial for genome maintenance in both bacteria and eukaryotes. RecQ helicases perform active destabilization of DNA duplexes, based on tight coupling of their ATPase activity to moderately processive translocation along DNA strands. Here, we determined the ATPase kinetic mechanism of E. coli RecQ helicase to reveal how mechanoenzymatic coupling is achieved. We found that the interaction of RecQ with DNA results in a drastic acceleration of the rate-limiting ATP cleavage step, which occurs productively due to subsequent rapid phosphate release. ADP release is not rate-limiting and ADP-bound RecQ molecules make up a small fraction during single-stranded DNA translocation. However, the relatively rapid release of the ADP-bound enzyme from DNA causes the majority of translocation run terminations (i.e. detachment from the DNA track). Thus, the DNA interactions of ADP-bound RecQ helicase, probably dependent on DNA structure, will mainly determine translocation processivity and may control the outcome of DNA processing. Comparison with human Bloom's syndrome (BLM) helicase reveals that similar macroscopic parameters are achieved by markedly different underlying mechanisms of RecQ homologs, suggesting diversity in enzymatic tuning. Oxford University Press 2015-01-30 2014-12-24 /pmc/articles/PMC4333385/ /pubmed/25539922 http://dx.doi.org/10.1093/nar/gku1333 Text en © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research. http://creativecommons.org/licenses/by/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Nucleic Acid Enzymes Sarlós, Kata Gyimesi, Máté Kele, Zoltán Kovács, Mihály Mechanism of RecQ helicase mechanoenzymatic coupling reveals that the DNA interactions of the ADP-bound enzyme control translocation run terminations |
title | Mechanism of RecQ helicase mechanoenzymatic coupling reveals that the DNA interactions of the ADP-bound enzyme control translocation run terminations |
title_full | Mechanism of RecQ helicase mechanoenzymatic coupling reveals that the DNA interactions of the ADP-bound enzyme control translocation run terminations |
title_fullStr | Mechanism of RecQ helicase mechanoenzymatic coupling reveals that the DNA interactions of the ADP-bound enzyme control translocation run terminations |
title_full_unstemmed | Mechanism of RecQ helicase mechanoenzymatic coupling reveals that the DNA interactions of the ADP-bound enzyme control translocation run terminations |
title_short | Mechanism of RecQ helicase mechanoenzymatic coupling reveals that the DNA interactions of the ADP-bound enzyme control translocation run terminations |
title_sort | mechanism of recq helicase mechanoenzymatic coupling reveals that the dna interactions of the adp-bound enzyme control translocation run terminations |
topic | Nucleic Acid Enzymes |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4333385/ https://www.ncbi.nlm.nih.gov/pubmed/25539922 http://dx.doi.org/10.1093/nar/gku1333 |
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