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Dna Synthesis Case Study

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To achieve accuracy of DNA replication after the unwinding of DNA, the DNA must be synthesized. DNA synthesis, in the case, the two strands are disconnected and then turned into single-stranded DNA. This is called replication fork. The replication fork acts as a model for DNA synthesis. However, the site of impaired or mutated DNA can cause a lower rate pf success for DNA synthesis. Impaired DNA can also lead to unprocessed and unligated okazaki fragments. Okazaki frgaments are small DNA fragments that are linked to the lagging strand of DNA. The research article suggest that okazaki fragemts should be tracked for the benefit of cancer patients. For instamce, the lack of DNA ligase 1 is caused by the delay of okazaki frgaments. DNA ligase 1…show more content…
An ubiquitin can change the way a cell functions or even where the call is located. The researchers then use a cdc9 with a wild-type of DNA ligase 1 to determine whether PCNA ubiquitination happens because of the nicked DNA or because of the lack of PCNA-DNA ligase interaction. While reviewing this, they noticed that the cdc9 mutants come to a halt during the later phases of the cell cycle and they collect unligated okazaki fragments. THis proves that PCNA ubiquitination occurs because of the nicked DNA. The nicks are left behind for repairin the last phase of the cell cycle, G2. Although they discovered this, they alos discovered that breaks in the DNA were present in the cdc9 mutants. They caused the replication forks to be held up. These breaks need to be repair via HR. To repair the breaks they suggest RAD52 to be used. Unfortunately, RAD52 was unsuccessful and did not interact with the mutant. They then test if RAD59 can be used to repair the breaks. THey recognize that RAD59 played an important role in supporting the kinase needed for checkpoint activation of the cell cycle, known s Mec1. However, RAD59instead deactivated Mec1 by restraining a protein coding gene called
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