Eukaryotic Replication Fork

Abstract

Abstract In eukaryotic cells, DNA ( deoxyribonucleic acid ) synthesis occurs at specific sites that move through the genome called replication forks. Multiprotein complexes at these forks catalyse the synthesis of two new strands of DNA using parental strands as templates to produce two complete copies of the parental DNA. The eukaryotic replication fork machinery must deal with the chromatin and chromosome structure of eukaryotic genomes, be able to replicate DNA in the context of a complex cell cycle, and be able to deal with the constant threat of mutations that could arise due to replication of damaged DNA, all while trying to efficiently replicate the DNA with high fidelity. The resulting eukaryotic replication fork is a tightly controlled, yet incredibly efficient biological machine capable of synthesizing billions of base pairs of DNA in the span of hours. Key Concepts: Eukaryotic DNA replication requires the concerted action of multiple DNA polymerases and accessory factors that replicate the DNA with high efficiency and accuracy. Eukaryotic chromosomes are replicated in a semidiscontinuous manner by replication forks that coordinate the simultaneous replication of the leading and lagging strands. The eukaryotic replication machinery is equipped to displace histones that coat chromatin DNA and reconstitute fully functional nucleoprotein chromosomes after DNA replication.