Replication | DNA Replication: Eukaryotic Origins and the Origin Recognition Complex

DNA replication in eukaryotes initiates from discrete regions in a genome called origins of DNA replication. Although origins appear site-specific, their usage and organization are rather plastic. The specification of replication sites and the timing of replication are dynamic processes that are regulated by tissue-specific, epigenetic and developmental cues. In eukaryotes, DNA replication begins with the binding of the six-subunit origin recognition complex (ORC) to the origins of DNA replication. ORC binds to the origin sites in an adenosine triphosphate-dependent manner and directs the assembly of the pre-replicative complex at the origins, thus licensing origins for DNA replication.