Single-molecule observation of ATP-independent SSB displacement by RecO in <i>Deinococcus radiodurans</i>.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32297860.
- Also identified by DOI 10.7554/eLife.50945 and PMC identifier 7200156.
- Licence recorded as CC0.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
<i>Deinococcus radiodurans</i> (DR) survives in the presence of hundreds of double-stranded DNA (dsDNA) breaks by efficiently repairing such breaks. RecO, a protein that is essential 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 that is generated by the fast diffusion of drSSB on ssDNA.
Medical subject headings
- Bacterial Proteins
- DNA Breaks, Single-Stranded
- DNA Repair
- Deinococcus
- Radiation Tolerance
- Recombinases