DNA replication

This chapter evaluates DNA replication, which occurs in three distinct phases: initiation, elongation, and termination. Initiation of replication in bacteria occurs at a unique chromosomal location called an origin, which is recognized by specific proteins. Initiation of replication in eukaryotes, in contrast, usually occurs stochastically at sites marked in the genome by binding of the pre-replication complex. New DNA strands are initiated by RNA or combined RNA and DNA primers, which are synthesized by primase in bacteria and the polymerase α-primase complex in eukaryotes. After their initial synthesis, the primers are then elongated by the replicative DNA polymerase. The termination of replication occurs when two replication forks traveling in opposite directions meet. The chapter then looks at the regulation of the initiation of DNA replication, the end-replication problem, and the replication of chromatin.