Search results
Results from the WOW.Com Content Network
DNA polymerase I (or Pol I) is an enzyme that participates in the process of prokaryotic DNA replication. Discovered by Arthur Kornberg in 1956, [1] it was the first known DNA polymerase (and the first known of any kind of polymerase). It was initially characterized in E. coli and is ubiquitous in prokaryotes.
Multiple DNA polymerases take on different roles in the DNA replication process. In E. coli, DNA Pol III is the polymerase enzyme primarily responsible for DNA replication. It assembles into a replication complex at the replication fork that exhibits extremely high processivity, remaining intact for the entire replication cycle.
In DNA replication, for example, formation of the phosphodiester bonds is catalyzed by a DNA polymerase enzyme, using a pair of magnesium cations and other supporting structures. [3] Formation of the bond occurs not only in DNA and RNA replication, but also in the repair and recombination of nucleic acids, and may require the involvement of ...
In DNA replication, DNA-dependent DNA polymerases make copies of DNA polynucleotide chains. To preserve biological information, it is essential that the sequence of bases in each copy are precisely complementary to the sequence of bases in the template strand. Many DNA polymerases have a proofreading activity. Here, the polymerase recognizes ...
A DNA polymerase is a member of a family of enzymes that catalyze the synthesis of DNA molecules from nucleoside triphosphates, the molecular precursors of DNA. These enzymes are essential for DNA replication and usually work in groups to create two identical DNA duplexes from a single original DNA duplex.
The extent of proofreading in DNA replication determines the mutation rate, and is different in different species. [4] For example, loss of proofreading due to mutations in the DNA polymerase epsilon gene results in a hyper-mutated genotype with >100 mutations per million bases of DNA in human colorectal cancers. [5]
DNA replication is the semi-conservative, biological process of two DNA strands copying themselves, resulting in two identical copies of DNA. [ 4 ] [ 5 ] This process is considered semi-conservative because, after replication, each copy of DNA contains a strand from the original DNA molecule and a strand from the newly-synthesized DNA molecule.
Because the binding of the polymerase to the template is the rate-limiting step in DNA synthesis [citation needed], the overall rate of DNA replication during S phase of the cell cycle is dependent on the processivity of the DNA polymerases performing the replication. DNA clamp proteins are integral components of the DNA replication machinery ...