Related topics: cancer cells · chromosomes · dna damage

Transcription factors may inadvertently lock in DNA mistakes

Transcription factor proteins are the light switches of the human genome. By binding to DNA, they help turn genes 'on' or 'off' and start the important process of copying DNA into an RNA template that acts as a blueprint ...

How to make a replication origin in multicellular eukaryotes

Loading of replicative helicases onto DNA is a key event during the initiation of chromosomal DNA replication. It takes place at specific chromosomal regions termed origins and is facilitated by the ORC protein complex. By ...

How cells keep growing even when under attack

In an unexpected new finding, biochemists at the University of Massachusetts Amherst report observing that a damage-containment system in stressed bacteria can become overrun and blocked, but that this leads to cells responding ...

Structural insights into Fe-S protein biogenesis

The cytosolic iron sulfur assembly (CIA) pathway is required for the insertion of Fe-S clusters into proteins, including many DNA replication and repair factors. Despite its essential cellular function, this pathway remains ...

page 1 from 21

DNA replication

DNA replication, the basis for biological inheritance, is a fundamental process occurring in all living organisms to copy their DNA. This process is "semiconservative" in that each strand of the original double-stranded DNA molecule serves as template for the reproduction of the complementary strand. Hence, following DNA replication, two identical DNA molecules have been produced from a single double-stranded DNA molecule. Cellular proofreading and error-checking mechanisms ensure near perfect fidelity for DNA replication.

In a cell, DNA replication begins at specific locations in the genome, called "origins". Unwinding of DNA at the origin, and synthesis of new strands, forms a replication fork. In addition to DNA polymerase, the enzyme that synthesizes the new DNA by adding nucleotides matched to the template strand, a number of other proteins are associated with the fork and assist in the initiation and continuation of DNA synthesis.

DNA replication can also be performed in vitro (outside a cell). DNA polymerases, isolated from cells, and artificial DNA primers are used to initiate DNA synthesis at known sequences in a template molecule. The polymerase chain reaction (PCR), a common laboratory technique, employs such artificial synthesis in a cyclic manner to amplify a specific target DNA fragment from a pool of DNA.

This text uses material from Wikipedia, licensed under CC BY-SA