Structural and Functional Characterization of RecG Helicase under Dilute and Molecular Crowding Conditions
In an ATP-dependent reaction, the Escherichia coli RecG helicase unwinds DNA junctions in vitro. We present evidence of a unique protein conformational change in the RecG helicase from an α-helix to a β-strand upon an ATP binding under dilute conditions using circular dichroism (CD) spectroscopy. In...
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| Format: | Article |
| Language: | English |
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Wiley
2012-01-01
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| Series: | Journal of Nucleic Acids |
| Online Access: | http://dx.doi.org/10.1155/2012/392039 |
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| author | Sarika Saxena Satoru Nagatoishi Daisuke Miyoshi Naoki Sugimoto |
| author_facet | Sarika Saxena Satoru Nagatoishi Daisuke Miyoshi Naoki Sugimoto |
| author_sort | Sarika Saxena |
| collection | DOAJ |
| description | In an ATP-dependent reaction, the Escherichia coli RecG helicase unwinds DNA junctions in vitro. We present evidence of a unique protein conformational change in the RecG helicase from an α-helix to a β-strand upon an ATP binding under dilute conditions using circular dichroism (CD) spectroscopy. In contrast, under molecular crowding conditions, the α-helical conformation was stable even upon an ATP binding. These distinct conformational behaviors were observed to be independent of Na+ and Mg2+. Interestingly, CD measurements demonstrated that the spectra of a frayed duplex decreased with increasing of the RecG concentration both under dilute and molecular crowding conditions in the presence of ATP, suggesting that RecG unwound the frayed duplex. Our findings raise the possibility that the α-helix and β-strand forms of RecG are a preactive and an active structure with the helicase activity, respectively. |
| format | Article |
| id | doaj-art-53f6499a024b4b188a7de1545cfa22b9 |
| institution | Kabale University |
| issn | 2090-0201 2090-021X |
| language | English |
| publishDate | 2012-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Journal of Nucleic Acids |
| spelling | doaj-art-53f6499a024b4b188a7de1545cfa22b92025-08-20T03:36:25ZengWileyJournal of Nucleic Acids2090-02012090-021X2012-01-01201210.1155/2012/392039392039Structural and Functional Characterization of RecG Helicase under Dilute and Molecular Crowding ConditionsSarika Saxena0Satoru Nagatoishi1Daisuke Miyoshi2Naoki Sugimoto3Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, JapanFrontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, JapanFrontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, JapanFrontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, JapanIn an ATP-dependent reaction, the Escherichia coli RecG helicase unwinds DNA junctions in vitro. We present evidence of a unique protein conformational change in the RecG helicase from an α-helix to a β-strand upon an ATP binding under dilute conditions using circular dichroism (CD) spectroscopy. In contrast, under molecular crowding conditions, the α-helical conformation was stable even upon an ATP binding. These distinct conformational behaviors were observed to be independent of Na+ and Mg2+. Interestingly, CD measurements demonstrated that the spectra of a frayed duplex decreased with increasing of the RecG concentration both under dilute and molecular crowding conditions in the presence of ATP, suggesting that RecG unwound the frayed duplex. Our findings raise the possibility that the α-helix and β-strand forms of RecG are a preactive and an active structure with the helicase activity, respectively.http://dx.doi.org/10.1155/2012/392039 |
| spellingShingle | Sarika Saxena Satoru Nagatoishi Daisuke Miyoshi Naoki Sugimoto Structural and Functional Characterization of RecG Helicase under Dilute and Molecular Crowding Conditions Journal of Nucleic Acids |
| title | Structural and Functional Characterization of RecG Helicase under Dilute and Molecular Crowding Conditions |
| title_full | Structural and Functional Characterization of RecG Helicase under Dilute and Molecular Crowding Conditions |
| title_fullStr | Structural and Functional Characterization of RecG Helicase under Dilute and Molecular Crowding Conditions |
| title_full_unstemmed | Structural and Functional Characterization of RecG Helicase under Dilute and Molecular Crowding Conditions |
| title_short | Structural and Functional Characterization of RecG Helicase under Dilute and Molecular Crowding Conditions |
| title_sort | structural and functional characterization of recg helicase under dilute and molecular crowding conditions |
| url | http://dx.doi.org/10.1155/2012/392039 |
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