Fidelity and processivity of Saccharomyces cerevisiae DNA polymerase eta.
The yeast RAD30 gene functions in error-free replication of UV-damaged DNA, and RAD30 encodes a DNA polymerase, pol eta, that has the ability to efficiently and correctly replicate past a cis-syn-thymine-thymine dimer in template DNA. To better understand the role of pol eta in damage bypass, we examined its fidelity and processivity on nondamaged DNA templates. Steady-state kinetic analyses of deoxynucleotide incorporation indicate that pol eta has a low fidelity, misincorporating deoxynucleotides with a frequency of about 10(-2) to 10(-3). Also pol eta has a low processivity, incorporating only a few nucleotides before dissociating. We suggest that pol eta's low fidelity reflects a flexibility in its active site rendering it more tolerant of DNA damage, while its low processivity limits its activity to reduce errors.
Washington
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Sealy Center for Molecular Science, University of Texas Medical Branch, Galveston, Texas 77555-1061, USA.
Johnson
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Prakash
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Prakash
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D004249:DNA Damage; D004261:DNA Replication; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D007700:Kinetics; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D000094769:DNA Polymerase iota; D000099270:Y-Family DNA Polymerases
D004259:DNA-Directed DNA Polymerase; D000094769:DNA Polymerase iota; C112338:Rad30 protein; D000099270:Y-Family DNA Polymerases