DNA Replication: Once, and only once

Once and only once upon a time: specifying and regulating origins of DNA replication in eukaryotic cells.

Right Place, Right Time, and Only Once: Replication Initiation in Metazoans

DNA replication is tightly regulated at the initiation step by both the cell cycle machinery and checkpoint pathways. Here, we discuss recent advances in understanding how replication is initiated in metazoans at the correct chromosome positions, at the appropriate time, and only once per cell cycle.

Conventional Dna Replication in Insects

Insect chromosomes provide wonderful model systems to unravel the mysteries of DNA replication. Data from studies of conventional replication of insect chromosomes are compatible with a mode of semidiscontinuous replication by a set of enzymes similar to those in mammals. Normally, replication initiates just once per S phase in each replicon. During various stages of insect development, however...

Lagging Strand Synthesis and Genomic Stability

In eukaryotic cells, DNA replication starts at many origins in each chromosome during S phase of cell cycle. Each origin is activated at different time points in S phase, which takes place once and only once per cell cycle. In yeast and most likely higher eukaryotes, the origin-recognition complex (ORC) and several other initiation factors play a pivotal role in activation and regulation of rep...

Deletion of the datA site does not affect once-per-cell-cycle timing but induces rifampin-resistant replication.

In Escherichia coli, three mechanisms have been proposed to maintain proper regulation of replication so that initiation occurs once, and only once, per cell cycle. First, newly formed origins are inactivated by sequestration; second, the initiator, DnaA, is inactivated by the Hda protein at active replication forks; and third, the level of free DnaA protein is reduced by replication of the dat...