期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2003
卷号：100
期号：21
页码：12093-12098
DOI：10.1073/pnas.2134223100
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：DNA polymerase {eta} (Pol{eta}) has the unique ability to replicate through UV-light-induced cyclobutane pyrimidine dimers. Here we use pre-steady-state kinetic analyses to examine the mechanism of nucleotide incorporation opposite a cis-syn thymine-thymine (TT) dimer and an identical nondamaged sequence by yeast Pol{eta}. Pol{eta} displayed "burst" kinetics for nucleotide incorporation opposite both the damaged and nondamaged templates. Although a slight decrease occurred in the affinity (Kd) of nucleotide binding opposite the TT dimer relative to the nondamaged template, the rate (kpol) of nucleotide incorporation was the same whether the template was damaged or nondamaged. These results strongly support a mechanism in which the nucleotide is directly inserted opposite the TT dimer by using its intrinsic base-pairing ability without any hindrance from the distorted geometry of the lesion.
