A single amino acid change (E85K) in human PCNA that leads, relative to wild type, to enhanced DNA synthesis by DNA polymerase delta nucleotide base lesions (TLS) as well as on unmodified templates

A study was conducted that compared wt human PCNA with mutant PCNA expressed from a human PCNA cDNA clonebearing a single nucleotide point mutation leading to the single amino acid replacement of lysine for glutamate at position 85 (E85K hPCNA). It concluded that human PCNA, either mutated to contain lysine (K) at position 85 or bearing similar primary mutations, would promote more secondary mutagenesis in cells and/or tissues where PCNA is normally expressed at low levels relative to pol delta.