DNA Replication (Essay Sample)

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DNA replication consists of biological processes that copies DNA. The process of replication begins at specific sites in the DNA known as the origin of replication. (DePamphilis 2010) explains that the process of DNA replication consists of three stages that are enzymatically catalyzed and coordinated: initiation, elongation and termination.
"At the initiation stage, an ordered assembly of initiator proteins is done at a specific location known as oriC," (Berg, 2002). This ordered assembly serves the purpose of ensuring that replication occurs only once. DnaA protein, a highly reserved protein in organisms, binds itself to the origin allowing for selective recruitment of proteins and enzymes that will lead to establishment of chromosomes for replication. DnaA protein is a vital tool in initiating replication. After combination with ATP and through assistance from bacterial histone like proteins HU, DnaA unwinds a region on the origin of replication, specifically at the oriC and opens up the DNA strand for further replication. DNA replication requires single stranded binding proteins to ensure the strands don’t re-anneal or form secondary structures.
(Allison, 2007) explains that replication occurs in a circular pattern resulting to formation of a shape similar to the Greek letter theta. Biochemist John Cairns in 1963 made a notable effort in demonstrating this theta structure. "Replication usually occurs in a bidirectional manner," (Albert, 2002) resulting to synthesis of strands. Later, deoxynucleotides are added to the DNA strand and integrated with DnaB helicase. The process of synthesis then continues as the DNA is being unwound.
Termination refers to a situation whereby two different DNA strands come about after fusion of the replicating cells. Termination occurs in the terminus region located opposite to the oriC where there are replication terminator sites. Eukaryotes are solely responsible for initiating DNA replication. However, eukaryotes usually have linear chromosomes, making it difficult for DNA replication ...