ABSTRACT
Pol ν is a 102 kDa protein whose gene is located on chromosome 4p16.3. Pol ν lacks a 3’-5’ proofreading exonuclease activity and has a moderate processivity, elongating 1-100 nucleotides (Marini et al. 2003; Takata et al. 2006; Arana et al. 2007). It catalyzes effi cient strand displacement on both non-damaged and damage (psoralen-induced ICL)-containing substrates (Takata et al. 2006; Zietlow et al. 2009). In vitro, pol ν replicates non-damaged DNA with low fi delity, primarily due to frequent misincorporation of dT opposite template dG, where the catalytic effi ciency of incorporation of an incorrect dT opposite a template dG is approximately half that of the error-free reaction (Takata et al. 2006; Arana et al. 2007). The frequency of nucleotide misincorporation opposite non-damaged nucleotides is ~10-1 to 10-4 (Takata et al. 2006). Additionally, studies using gapped M13mp2 plasmids found that during synthesis of the target lacZα gene, the frequency of lacZ mutants generated by pol ν was 2.3 percent when reactions were carried out at neutral pH, yet was 18 percent when reactions were carried out at alkaline pH (Arana et al. 2007, 2008). Furthermore, the polymerase can catalyze nontemplated nucleotide addition at a blunt end (Takata et al. 2006).
