Stabilization of DNA fork junctions by Smc5/6 complexes revealed by single-molecule imaging

Tanasie, Nicoleta-Loredana; Gutiérrez-Escribano, Pilar; Jaklin, Sigrun; Aragon, Luis und Stigler, Johannes (6. December 2022): Stabilization of DNA fork junctions by Smc5/6 complexes revealed by single-molecule imaging. In: Cell Reports, Vol. 41, No. 10

Abstract

SMC complexes play key roles in genome maintenance, where they ensure efficient genome replication and segregation. The SMC complex Smc5/6 is a crucial player in DNA replication and repair, yet many molecular features that determine its roles are unclear. Here, we use single-molecule microscopy to investigate Smc5/6’s interaction with DNA. We find that Smc5/6 forms oligomers that dynamically redistribute on dsDNA by 1D diffusion and statically bind to ssDNA. Using combined force manipulation and single-molecule microscopy, we generate ssDNA-dsDNA junctions that mimic structures present in DNA repair intermediates or replication forks. We show that Smc5/6 accumulates at these junction sites, stabilizes the fork, and promotes the retention of RPA. Our observations provide a model for the complex’s enrichment at sites of replication stress and DNA lesions from where it coordinates the recruitment and activation of downstream repair proteins.

• Item Type: Journal article
• Form of publication: Publisher's Version
• Faculties: Chemistry and Pharmacy > Department of Biochemistry
• Subjects: 500 Science > 540 Chemistry
• ISSN: 22111247
• Language: English
• DFG: Gefördert durch die Deutsche Forschungsgemeinschaft (DFG) - 491502892