Research had conducted to study nucleotide excision repair DNA synthesis by DNA polymerase epsilon in the presence of PCNA (proliferating cell nuclear antigen), RFC (replication factor C) and RPA (replication protein A). Either DNA polymerase epsilon or DNA polymerase delta along with DNA ligase can be used to repair UV-damaged DNA. However, it is found that DNA polymerase delta require the presence of both RFC and PCNA in order in DNA repair. In addition, it only produces small amount of fractionated DNA ligated products. DNA polymerase epsilon proves to be best suited for nucleotide excision repair. DNA polymerase epsilon is independent of both PCNA and RFC, and produces mostly ligated DNA products. It is also found that under one condition where DNA polymerase epsilon require PCNA and RFC: nucleotide excision repair in the presence of single strand binding protein RPA. PCNA and RFC function as anchor and direct DNA polymerase epsilon onto the DNA template.
^Shivji MK, Podust VN, Hübscher U, Wood RD (April 1995). "Nucleotide excision repair DNA synthesis by DNA polymerase epsilon in the presence of PCNA, RFC, and RPA". Biochemistry. 34 (15): 5011–7. doi:10.1021/bi00015a012. PMID7711023.