Single-molecule observation of ATP-independent SSB displacement by RecO in Deinococcus radiodurans
- Seoul National University, Republic of Korea
- National Institutes of Health, United States
- Daegu National Science Museum, Republic of Korea
- Pohang University of Science and Technology, Republic of Korea
Abstract
Deinococcus radiodurans (DR) survives in the presence of hundreds of double-stranded DNA (dsDNA) breaks by efficiently repairing such breaks. RecO, an essential protein for the extreme radioresistance of DR, is one of the major recombination mediator proteins in the RecA-loading process in the RecFOR pathway. However, how RecO participates in the RecA-loading process is still unclear. In this work, we investigated the function of drRecO using single-molecule techniques. We found that drRecO competes with the ssDNA binding protein (drSSB) for binding to the freely exposed ssDNA and efficiently displaces drSSB from ssDNA without consuming ATP. drRecO replaces drSSB and dissociates it completely from ssDNA even though drSSB binds to ssDNA approximately 300 times more strongly than drRecO does. We suggest that drRecO facilitates the loading of RecA onto drSSB-coated ssDNA by utilizing a small drSSB-free space on ssDNA generated by the fast diffusion of drSSB on ssDNA.
Data availability
All data generated or analysed during this study are included in the manuscript and supporting files. Source data files (459GB video images) are available upon request.
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Author details
Funding
National Research Foundation of Korea (NRF-2017R1A2B3010309)
- Nam Ki Lee
National Research Foundation of Korea (NRF-2018R1A2B2001422)
- Seong Keun Kim
National Research Foundation of Korea (NRF-2019R1A2C2090896)
- Nam Ki Lee
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.
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Single-molecule observation of ATP-independent SSB displacement by RecO in Deinococcus radiodurans
eLife 9:e50945.
https://doi.org/10.7554/eLife.50945
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