RPA promotes processive ssDNA digestion by Dna2 via their bimodal interaction in Saccharomyces cerevisiae

ABSTRACT: Single-stranded DNA (ssDNA) widely exists as intermediates in DNA metabolic pathways. The ssDNA binding protein, RPA, not only protects the integrity of ssDNA, but also directs the downstream factor that signals or repairs the ssDNA intermediate. However, it remains unclear how these enzymes/factors out-compete RPA and access to ssDNA. Using the budding yeast, Saccharomyces cerevisiae, as a model system, we discovered that Dna2, a key nuclease in DNA replication and repair, employs a bimodal interface to act with RPA both in cis and in trans. The cis-action renders RPA a processive unit for Dna2-catalyzed ssDNA digestion, where RPA actively delivers its bound ssDNA to Dna2. The trans-action mediated by an acidic patch from Dna2, on the other hand, enables Dna2 to operatie with a sub-optimal amount of RPA or to overcome DNA secondary structures. Genetically, this trans-action mode is not required for cell viability, but indispensable for successful DSB repair.

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Saccharomyces Cerevisiae (baker's Yeast)

SUBMITTER: Yixiang Zhang  

LAB HEAD: Hengyao Niu

PROVIDER: PXD028637 | Pride | 2022-02-22

REPOSITORIES: Pride