| Autor: |
Burns, J L, Guzder, S N, Sung, P, Prakash, S, Prakash, L |
| Zdroj: |
Journal of Biological Chemistry; May 1996, Vol. 271 Issue: 20 p11607-10, 4p |
| Abstrakt: |
Replication protein A (RPA), a heterotrimeric protein of 70-, 32-, and 14-kDa subunits, is an essential factor for DNA replication. Biochemical studies with human and yeast RPA have indicated that it is a DNA-binding protein that has higher affinity for single-stranded DNA. Interestingly, in vitro nucleotide excision repair studies with purified protein components have shown an absolute requirement for RPA in the incision of UV-damaged DNA. Here we use a mobility shift assay to demonstrate that human RPA binds a UV damaged duplex DNA fragment preferentially. Complex formation between RPA and the UV-irradiated DNA is not affected by prior enzymatic photo-reactivation of the DNA, suggesting an affinity of RPA for the (6-4) photoproduct. We also show that Mg2+ in the millimolar range is required for preferential binding of RPA to damaged DNA. These findings identify a novel property of RPA and implicate RPA in damage recognition during the incision of UV-damaged DNA. |
| Databáze: |
Supplemental Index |
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