Molecular determinants of Smc5/6 association with DNA junctions.
| Publication Type | Academic Article |
| Authors | Chang J, Miller-Browne V, Chua G, Zheng J, Beckwitt E, Li S, Katch B, O'Donnell M, Liu S, Zhao X |
| Journal | Nat Commun |
| Volume | 17 |
| Issue | 1 |
| Pagination | 1239 |
| Date Published | 01/17/2026 |
| ISSN | 2041-1723 |
| Keywords | Cell Cycle Proteins, DNA, Single-Stranded, Schizosaccharomyces pombe Proteins, DNA, Fungal, DNA |
| Abstract | Smc5/6 is an essential genome maintenance complex that interacts with double-stranded (ds) DNA, single-stranded (ss) DNA, and ss-dsDNA junctions. DNA association underlies Smc5/6's functions in managing intermediates generated during genome replication and repair. However, the mechanisms of this activity are not fully understood. Here, we report a single-molecule study examining Smc5/6 association with a dsDNA substrate containing a ssDNA gap with defined 3' and 5' junctions. We found that Smc5/6 associates with both 3' and 5' junctions but prefers the 3' junction in the presence of the ssDNA-binding complex RPA. Further, Smc5/6's junction association frequency and dwell time are regulated by two non-SMC subcomplexes and DNA binding residues of Smc6. Moreover, Smc5/6 prefers binding to junction sites free of the sliding clamp PCNA over those occupied with it. These results suggest that Smc5/6 utilizes its multiple structural modules to associate with junction sites in coordination with other genome maintenance factors. |
| DOI | 10.1038/s41467-025-67999-5 |
| PubMed ID | 41547900 |
| PubMed Central ID | PMC12864806 |