TY - JOUR A2 - Basu, Ashis AU - Brown, Jessica A. AU - Zhang, Likui AU - Sherrer, Shanen M. AU - Taylor, John-Stephen AU - Burgers, Peter M. J. AU - Suo, Zucai PY - 2010 DA - 2010/07/25 TI - Pre-Steady-State Kinetic Analysis of Truncated and Full-Length Saccharomyces cerevisiae DNA Polymerase Eta SP - 871939 VL - 2010 AB - Understanding polymerase fidelity is an important objective towards ascertaining the overall stability of an organism's genome. Saccharomyces cerevisiae DNA polymerase η (yPolη), a Y-family DNA polymerase, is known to efficiently bypass DNA lesions (e.g., pyrimidine dimers) in vivo. Using pre-steady-state kinetic methods, we examined both full-length and a truncated version of yPolη which contains only the polymerase domain. In the absence of yPolη's C-terminal residues 514–632, the DNA binding affinity was weakened by 2-fold and the base substitution fidelity dropped by 3-fold. Thus, the C-terminus of yPolη may interact with DNA and slightly alter the conformation of the polymerase domain during catalysis. In general, yPolη discriminated between a correct and incorrect nucleotide more during the incorporation step (50-fold on average) than the ground-state binding step (18-fold on average). Blunt-end additions of dATP or pyrene nucleotide 5-triphosphate revealed the importance of base stacking during the binding of incorrect incoming nucleotides. SN - 2090-0201 UR - https://doi.org/10.4061/2010/871939 DO - 10.4061/2010/871939 JF - Journal of Nucleic Acids PB - SAGE-Hindawi Access to Research KW - ER -