The architecture and function of the chromatin replication machinery

- The eukaryotic replisome functions on chromatin, not just DNA, and interactions with histones are critical for efficient replication.
- Electron microscopy studies on the replicative helicase and polymerases provide new insight into replisome mechanics.
- Crystal structures of replication-coupled histone chaperones suggest mechanisms for replicating epigenetic information.
- The latest data can be integrated into new models for chromatin replication.

Genomic DNA in eukaryotic cells is packaged into nucleosome arrays. During replication, nucleosomes need to be dismantled ahead of the advancing replication fork and reassembled on duplicated DNA. The architecture and function of the core replisome machinery is now beginning to be elucidated, with recent insights shaping our view on DNA replication processes. Simultaneously, breakthroughs in our mechanistic understanding of epigenetic inheritance allow us to build new models of how histone chaperones integrate with the replisome to reshuffle nucleosomes. The emerging picture indicates that the core eukaryotic DNA replication machinery has evolved elements that handle nucleosomes to facilitate chromatin duplication.

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