Pruss D, Reeves R, Bushman F D, Wolffe A P
Laboratory of Molecular Embryology, NICHHD, National Institutes of Health, Bethesda, Maryland 20892.
J Biol Chem. 1994 Oct 7;269(40):25031-41.
DNA copies of the human immunodeficiency virus (HIV) genome integrate nonrandomly into the chromosomal DNA of the host cell. In this report, we investigate the molecular basis of this selectivity using the virus-encoded HIV integrase to direct integration of a synthetic HIV long terminal repeat substrate into either DNA molecules of known structure or previously defined nucleosomal complexes. We find that the structure of the target greatly influences the site of integration, and, moreover, DNA curvature, flexibility, and rigidity in solution all influence the frequency of integration. Importantly, for DNA with all of these properties, the distortion of the double helix directed by association with the histone proteins promotes the integration reaction and alters the distribution of sites that are selected for integration. We suggest that both intrinsic DNA structure and the folding of DNA into chromosomal structures will exert a major influence on target site selection for integration of the viral genome.
人类免疫缺陷病毒（HIV）基因组的DNA拷贝会非随机地整合到宿主细胞的染色体DNA中。在本报告中，我们利用病毒编码的HIV整合酶，将合成的HIV长末端重复序列底物整合到已知结构的DNA分子或先前定义的核小体复合物中，以此来研究这种选择性的分子基础。我们发现，靶标的结构对整合位点有很大影响，此外，溶液中DNA的曲率、柔韧性和刚性都会影响整合频率。重要的是，对于具有所有这些特性的DNA，与组蛋白结合所导致的双螺旋扭曲会促进整合反应，并改变被选择用于整合的位点分布。我们认为，DNA的固有结构以及DNA折叠成染色体结构的过程都会对病毒基因组整合的靶位点选择产生重大影响。
