• BMB Reports
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• v.34 no.6
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• pp.489-495
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• 2001

DNA damage by UV and environmental agents are the major cause of genomic instability that needs to be repaired, otherwise it give rise to cancer. Accordingly, mammalian cells operate several DNA repair pathways that are not only responsible for identifying various types of DNA damage but also involved in removing DNA damage. In mammals, nucleotide excision repair (NER) machinery is responsible for most, if not all, of the bulky adducts caused by UV and chemical agents. Although most of the proteins involved in NER pathway have been identified, only recently have we begun to gain some insight into the mechanism by which proteins recognize damaged DNA. Binding of Xeroderma pigmentosum group C protein (XPC)-hHR23B complex to damaged DNA is the initial damage recognition step in NER, which leads to the recruitment of XPA and RPA to form a damage recognition complex. Formation of damage recognition complex not only stabilizes low affinity binding of XPA to the damaged DNA, but also induces structural distortion, both of which are likely necessary for the recruitment of TFIIH and two structure-specific endonucleases for dual incision.

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.3005-3008
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• 2014

Human ChlR1 protein (hChlR1), a member of the cohesion establishment factor family, plays an important role in the segregation of sister chromatids for maintenance of genome integrity. We previously reported that hChlR1 interacts with hFen1 and stimulates its nuclease activity on the flap-structured DNA substrate covered with RPA. To elucidate the relationship between hChlR1 and Okazaki fragment processing, the effect of hChlR1 on in vitro nuclease activities of hFen1 and hDna2 was examined. Independent of ATPase activity, hChlR1 stimulated endonuclease activity of hFen1 but not that of hDna2. Our findings suggest that the acceleration of Okazaki fragment processing near cohesions may aid in reducing the size of the replication machinery, thereby facilitating its entry through the cohesin ring.