Search results
Results From The WOW.Com Content Network
Prokaryotic DNA Replication is the process by which a prokaryote duplicates its DNA into another copy that is passed on to daughter cells. [1] Although it is often studied in the model organism E. coli, other bacteria show many similarities. [2] Replication is bi-directional and originates at a single origin of replication (OriC). [3]
Meister's finding is the first direct evidence of replication factory model. Subsequent research has shown that DNA helicases form dimers in many eukaryotic cells and bacterial replication machineries stay in single intranuclear location during DNA synthesis. [49] Replication Factories Disentangle Sister Chromatids.
MCM2-7 is required for both DNA replication initiation and elongation; its regulation at each stage is a central feature of eukaryotic DNA replication. [3] During G1 phase, the two head-to-head Mcm2-7 rings serve as the scaffold for the assembly of the bidirectional replication initiation complexes at the replication origin.
This mechanism is conserved from prokaryotes to eukaryotes and is known as semiconservative DNA replication. The process of semiconservative replication for the site of DNA replication is a fork-like DNA structure, the replication fork, where the DNA helix is open, or unwound, exposing unpaired DNA nucleotides for recognition and base pairing ...
More than five decades ago, Jacob, Brenner, and Cuzin proposed the replicon hypothesis to explain the regulation of chromosomal DNA synthesis in E. coli. [18] The model postulates that a diffusible, trans-acting factor, a so-called initiator, interacts with a cis-acting DNA element, the replicator, to promote replication onset at a nearby origin.
This timing and other regulatory mechanisms ensure that DNA replication will only occur once per cell cycle. Assembly of the pre-RC relies on prior origin recognition, either by DnaA in prokaryotes or by ORC in archaea and eukaryotes. The pre-RC of prokaryotes is complete when DnaA occupies all possible binding sites within the oriC.
Regulation of gene expression, or gene regulation, [1] includes a wide range of mechanisms that are used by cells to increase or decrease the production of specific gene products (protein or RNA). Sophisticated programs of gene expression are widely observed in biology, for example to trigger developmental pathways, respond to environmental ...
DNA re-replication (or simply rereplication) is an undesirable and possibly fatal occurrence in eukaryotic cells in which the genome is replicated more than once per cell cycle. [1] Rereplication is believed to lead to genomic instability and has been implicated in the pathologies of a variety of human cancers. [2]