Proliferating Cell Nuclear Antigen Promotes Translesion Synthesis by DNA Polymerase ζ

• Published in: The Journal of biological chemistry Vol. 280; no. 25; pp. 23446 - 23450
• Main Authors: Garg, Parie, Stith, Carrie M., Majka, Jerzy, Burgers, Peter M.J.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 24-06-2005
• Subjects: Base Sequence; DNA Damage; DNA Primers; DNA Repair - physiology; DNA-Directed DNA Polymerase - isolation & purification; DNA-Directed DNA Polymerase - metabolism; Proliferating Cell Nuclear Antigen - physiology; Ultraviolet Rays
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.C500173200

DNA polymerase ζ (Pol ζ), a heterodimer of Rev3 and Rev7, is essential for DNA damage provoked mutagenesis in eukaryotes. DNA polymerases that function in a processive complex with the replication clamp proliferating cell nuclear antigen (PCNA) have been shown to possess a close match to the consensus PCNA-binding motif QxxLxxFF. This consensus motif is lacking in either subunit of Pol ζ, yet its activity is stimulated by PCNA. In particular, translesion synthesis of UV damage-containing DNA is dramatically stimulated by PCNA such that translesion synthesis rates are comparable with replication rates by Pol ζ on undamaged DNA. PCNA also stimulated translesion synthesis of a model abasic site by Pol ζ. Efficient PCNA stimulation required that PCNA was prevented from sliding off the damage-containing model oligonucleotide template-primer through the use of biotin-streptavidin bumpers or other blocks. Under those experimental conditions, facile bypass of the abasic site was also detected by DNA polymerase δ or η (Rad30). The yeast DNA damage checkpoint clamp, consisting of Rad17, Mec3, and Ddc1, and an ortholog of human 9-1-1, has been implicated in damage-induced mutagenesis. However, this checkpoint clamp did not stimulate translesion synthesis by Pol ζ or by DNA polymerase δ.