Unravelling How Single-Stranded DNA Binding Protein Coordinates DNA Metabolism Using Single-Molecule Approaches

Single-stranded DNA-binding proteins (SSBs) play vital roles in DNA metabolism. Proteins of the SSB family exclusively and transiently bind to ssDNA, preventing the DNA double helix from re-annealing and maintaining genome integrity. In the meantime, they interact and coordinate with various proteins vital for DNA replication, recombination, and repair. Although SSB is essential for DNA metabolism, proteins of the SSB family have been long described as accessory players, primarily due to their unclear dynamics and mechanistic interaction with DNA and its partners. Recently-developed single-molecule tools, together with biochemical ensemble techniques and structural methods, have enhanced our understanding of the different coordination roles that SSB plays during DNA metabolism. In this review, we discuss how single-molecule assays, such as optical tweezers, magnetic tweezers, Forster resonance energy transfer, and their combinations, have advanced our understanding of the binding dynamics of SSBs to ssDNA and their interaction with other proteins partners. We highlight the central coordination role that the SSB protein plays by directly modulating other proteins' activities, rather than as an accessory player. Many possible modes of SSB interaction with protein partners are discussed, which together provide a bigger picture of the interaction network shaped by SSB.

Automated summary

Single-stranded DNA-binding proteins (SSBs) are essential for DNA metabolism and play crucial roles in maintaining genome integrity and coordinating with other proteins involved in DNA replication, recombination, and repair. Recent advances in single-molecule techniques and structural methods have greatly improved our understanding of the binding dynamics and interaction of SSBs with ssDNA and other protein partners. We highlight the central coordination role of SSBs in directly modulating the activities of other proteins and discuss the various modes of interaction between SSBs and their protein partners, providing a comprehensive view of the interaction network shaped by SSBs.