4 years ago

RecQ helicase triggers a binding mode change in the SSB-DNA complex to efficiently initiate DNA unwinding.

Yeonee Seol, Gábor M Harami, Máté Martina, Mihály Kovács, Keir C Neuman, Zoltán J Kovács, Maria Mills, Máté Gyimesi
The single-stranded DNA binding protein (SSB) of Escherichia coli plays essential roles in maintaining genome integrity by sequestering ssDNA and mediating DNA processing pathways through interactions with DNA-processing enzymes. Despite its DNA-sequestering properties, SSB stimulates the DNA processing activities of some of its binding partners. One example is the genome maintenance protein RecQ helicase. Here, we determine the mechanistic details of the RecQ-SSB interaction using single-molecule magnetic tweezers and rapid kinetic experiments. Our results reveal that the SSB-RecQ interaction changes the binding mode of SSB, thereby allowing RecQ to gain access to ssDNA and facilitating DNA unwinding. Conversely, the interaction of RecQ with the SSB C-terminal tail increases the on-rate of RecQ-DNA binding and has a modest stimulatory effect on the unwinding rate of RecQ. We propose that this bidirectional communication promotes efficient DNA processing and explains how SSB stimulates rather than inhibits RecQ activity.

Publisher URL: http://doi.org/10.1093/nar/gkx939

DOI: 10.1093/nar/gkx939

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.