Structure of eukaryotic DNA polymerase δ bound to the PCNA clamp while encircling DNA
Fengwei Zheng, Roxana E. Georgescu, Huilin Li, Mike O’Donnell
Abstract
Significance The structure of the eukaryotic chromosomal replicase, DNA polymerase (Pol) δ, was determined in complex with its cognate proliferating cell nuclear antigen (PCNA) sliding clamp on primed DNA. The results show that the Pol3 catalytic subunit binds atop the PCNA ring, and the two regulatory subunits of Pol δ, Pol31, and Pol32, are positioned off to the side of the Pol3 clamp. The catalytic Pol3 binds DNA and PCNA such as to thread the DNA straight through the circular PCNA clamp. Considering the large diameter of the PCNA clamp, there is room for water between DNA and the inner walls of PCNA, indicating the clamp “waterskates” on DNA during function with polymerase.
Topics & Concepts
Proliferating cell nuclear antigenDNA clampDNA polymeraseDNA polymerase deltaDNA polymerase IIMolecular biologyClampReplication factor CBiologyProcessivityDNABiophysicsCell biologyEukaryotic DNA replicationBiochemistryReverse transcriptasePolymerase chain reactionGeneEngineeringMechanical engineeringClampingDNA Repair MechanismsGenomics and Chromatin DynamicsBacterial Genetics and Biotechnology