Gale J M, Smerdon M J
Biochemistry/Biophysics Program, Washington State University, Pullman 99164-4660.
Photochem Photobiol. 1990 Apr;51(4):411-7. doi: 10.1111/j.1751-1097.1990.tb01732.x.
We have compared the distributions of two stable UV photoproducts in nucleosome core DNA at the single-nucleotide level using a T4 polymerase-exonuclease mapping procedure. The distribution of pyrimidine-pyrimidone (6-4) dimers was uncovered by reversing the major UV photo-product, cis-syn cyclobutane pyrimidine dimer, with E. coli DNA photolyase and photoreactivating light. Whereas the distribution of total UV photoproducts in nucleosome core DNA forms a striking 10.3 base periodic pattern, the distribution of (6-4) dimers is much more random throughout the nucleosome core domain. Therefore, histone-DNA interactions in nucleosomes strongly modulate formation of the major class of UV-induced photoproducts, while having either a constant effect or no effect on (6-4) dimer formation.
我们使用T4聚合酶-核酸外切酶作图程序，在单核苷酸水平上比较了核小体核心DNA中两种稳定的紫外线光产物的分布。通过用大肠杆菌DNA光解酶和光复活光逆转主要的紫外线光产物顺式-顺式环丁烷嘧啶二聚体，揭示了嘧啶-嘧啶酮（6-4）二聚体的分布。虽然核小体核心DNA中总紫外线光产物的分布形成了显著的10.3碱基周期性模式，但（6-4）二聚体的分布在整个核小体核心区域更为随机。因此，核小体中的组蛋白-DNA相互作用强烈调节主要类别的紫外线诱导光产物的形成，而对（6-4）二聚体的形成要么有恒定影响，要么没有影响。
