Chromatin Constrains the Initiation and Elongation of DNA Replication

• DOI: 10.1016/j.molcel.2016.10.035
• Publication Date: 2016-12-15T18:46:25Z
• Authors: Sujan Devbhandari; Jieqing Jiang; Charanya Kumar; Iestyn Whitehouse; Dirk Remus
• Keywords: Okazaki fragments; Pre-replication complex; Origin recognition complex

Eukaryotic chromosomal DNA is faithfully replicated in a complex series of cell-cycle-regulated events that are incompletely understood. Here we report the reconstitution of DNA replication free in solution with purified proteins from the budding yeast Saccharomyces cerevisiae. The system recapitulates regulated bidirectional origin activation; synthesis of leading and lagging strands by the three replicative DNA polymerases Pol α, Pol δ, and Pol ε; and canonical maturation of Okazaki fragments into continuous daughter strands. We uncover a dual regulatory role for chromatin during DNA replication: promoting origin dependence and determining Okazaki fragment length by restricting Pol δ progression. This system thus provides a functional platform for the detailed mechanistic analysis of eukaryotic chromosome replication.