In eukaryotic DNA replication, the prereplication complex (preRC) assembles at the origin of replication, which contains specific nucleic acid sequences called . Multiple protein components must assemble, including the origin recognition complex (ORC), , and other proteins. When all components of the preRC are bound, this completes a process called . This process is important because it helps ensure that all origins of replication on all the chromosomes are ready to begin replication at the same time.