PCNA binding domains in all three subunits of yeast DNA polymerase δ modulate its function in DNA replication
- 14 October 2011
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences of the United States of America
- Vol. 108 (44), 17927-17932
- https://doi.org/10.1073/pnas.1109981108
Abstract
DNA polymerase δ (Polδ) plays an essential role in replication from yeast to humans. Polδ in Saccharomyces cerevisiae is comprised of three subunits, the catalytic subunit Pol3 and the accessory subunits Pol31 and Pol32. Yeast Polδ exhibits a very high processivity in synthesizing DNA with the proliferating cell nuclear antigen (PCNA) sliding clamp; however, it has remained unclear how Polδ binds PCNA to achieve its high processivity. Here we show that PCNA interacting protein (PIP) motifs in all three subunits contribute to PCNA-stimulated DNA synthesis by Polδ, and mutational inactivation of all three PIP motifs abrogates its ability to synthesize DNA with PCNA. Genetic analyses of mutations in these PIPs have revealed that in the absence of functional Pol32 PIP domain, PCNA binding by both the Pol3 and Pol31 subunits becomes essential for cell viability. Based on our biochemical and genetic studies we infer that yeast Polδ can simultaneously utilize all three PIP motifs during PCNA-dependent DNA synthesis, and suggest that Polδ binds the PCNA homotrimer via its three subunits. We consider the implications of these observations for Polδ’s role in DNA replication.Keywords
This publication has 34 references indexed in Scilit:
- Structural Insights into Yeast DNA Polymerase δ by Small Angle X-ray ScatteringJournal of Molecular Biology, 2009
- DNA Polymerase δ Is Highly Processive with Proliferating Cell Nuclear Antigen and Undergoes Collision Release upon Completing DNAPublished by Elsevier BV ,2008
- Division of Labor at the Eukaryotic Replication ForkMolecular Cell, 2008
- Yeast DNA Polymerase ε Participates in Leading-Strand DNA ReplicationScience, 2007
- Structural analysis of a eukaryotic sliding DNA clamp–clamp loader complexNature, 2004
- The Pol32 Subunit of DNA Polymerase δ Contains Separable Domains for Processive Replication and Proliferating Cell Nuclear Antigen (PCNA) BindingJournal of Biological Chemistry, 2004
- Mediation of Proliferating Cell Nuclear Antigen (PCNA)-dependent DNA Replication through a Conserved p21Cip1-like PCNA-binding Motif Present in the Third Subunit of Human DNA Polymerase δPublished by Elsevier BV ,2001
- Multiple competition reactions for RPA order the assembly of the DNA polymerase delta holoenzymeThe EMBO Journal, 1999
- DNA Polymerase ε Catalytic Domains Are Dispensable for DNA Replication, DNA Repair, and Cell ViabilityMolecular Cell, 1999
- Characterization of the Two Small Subunits of Saccharomyces cerevisiae DNA Polymerase δJournal of Biological Chemistry, 1998