Rdh54/Tid1 inhibits Rad51-Rad54-mediated D-loop formation and limits D-loop length.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33185188.
- Also identified by DOI 10.7554/eLife.59112 and PMC identifier 7695457.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Displacement loops (D-loops) are critical intermediates formed during homologous recombination. Rdh54 (a.k.a. Tid1), a Rad54 paralog in <i>Saccharomyces cerevisiae,</i> is well-known for its role with Dmc1 recombinase during meiotic recombination. Yet contrary to Dmc1, Rdh54/Tid1 is also present in somatic cells where its function is less understood. While Rdh54/Tid1 enhances the Rad51 DNA strand invasion activity in vitro, it is unclear how it interplays with Rad54. Here, we show that Rdh54/Tid1 inhibits D-loop formation by Rad51 and Rad54 in an ATPase-independent manner. Using a novel D-loop Mapping Assay, we further demonstrate that Rdh54/Tid1 uniquely restricts the length of Rad51-Rad54-mediated D-loops. The alterations in D-loop properties appear to be important for cell survival and mating-type switch in haploid yeast. We propose that Rdh54/Tid1 and Rad54 compete for potential binding sites within the Rad51 filament, where Rdh54/Tid1 acts as a physical roadblock to Rad54 translocation, limiting D-loop formation and D-loop length.
Medical subject headings
- DNA Helicases
- DNA Repair
- DNA Repair Enzymes
- DNA Topoisomerases
- Rad51 Recombinase
- Saccharomyces cerevisiae Proteins