STRUCTURE OF DAMAGED DNA

产品说明：本研究的长期目标是建立DNA加合物和相关损伤的三维结构，并将选择性损伤的DNA的结构特征与其热力学性质和生物学过程（包括诱变和DNA修复）相关联。 在少数补充的支持下，我们利用高分辨率NMR光谱和分子动力学来建立含有环外病变和无碱基位点的DNA双链体的溶液结构，确定它们的全局结构特征，含有病变的碱基排列和病变位点处或附近的扰动。 我们未来的研究包括三个方面：（i）新的DNA加合物，（ii）DNA脱碱基位点，（iii）受损的DNA/修复蛋白复合物。我们将对含有损伤的DNA双链体进行研究，重点是乙烯基，丙烯醛和FaPy-dG，氧化DNA损伤和脂质过氧化产生的加合物。 将确定这些病变与典型沃森-克里克配偶体和致突变中间体配对的结构。我们将通过建立糖构型、C1、氢键和脱碱基位点的螺旋内或螺旋外位置之间的相关性来扩展我们对脱碱基位点的研究。 此外，我们将表征双链无碱基位点病变，以评估DNA双链体中序列背景、错配形成和方向性的影响。 我们还将确定一个假定的“翻转”DNA中间体的三维结构，当MutY结合到一个不可切割的DNA底物时形成，并将建立一个解决方案结构的C-末端结构域MutY蛋白。

DESCRIPTION: (Applicant's Description) The long-term goal of this research is to establish three-dimensional structures of DNA adducts and related lesions, and to correlate structural features of selectively-damaged DNA with its thermodynamic properties and with biological processes, including mutagenesis and DNA repair. Supported by a minority supplement, we have utilized high-resolution NMR spectroscopy and molecular dynamics to establish solution structures of DNA duplexes containing exocyclic lesions and abasic sites, determining their global structural features, lesion-containing base alignments, and perturbations at or near the lesion site. Our future studies encompass three areas: (i) novel DNA adducts, (ii) DNA abasic sites, and (iii) damaged DNA/repair protein complexes. We will perform studies on lesion-containing DNA duplexes focusing on etheno-, acrolein-, and FaPy-dG, adducts resulting from oxidative DNA damage and lipid peroxidation. The structure of these lesions paired with canonical Watson-Crick partners and mutagenic intermediates will be established. We will extend our studies of abasic sites by establishing correlations between sugar configuration, C1, hydrogen bonding, and the intra- or extrahelical position of the abasic site. In addition, we will characterize bistrand abasic site lesions to evaluate the effects of sequence context, mismatch formation, and directionality in DNA duplexes. We also will determine the three-dimensional structure of a putative "flipped-out" DNA intermediate that forms when MutY binds to a non-cleavable DNA substrate, and will establish a solution structure for the C-terminal domain MutY protein.