Gerton J L, Herschlag D, Brown P O
Department of Microbiology, Stanford University Medical Center, Stanford, California 94305-5428, USA.
J Biol Chem. 1999 Nov 19;274(47):33480-7. doi: 10.1074/jbc.274.47.33480.
The retroviral integrase catalyzes two successive chemical reactions essential for integration of the retroviral genome into a host chromosome: 3' end processing, in which a dinucleotide is cleaved from each 3' end of the viral DNA; and the integration reaction itself, in which the resulting recessed 3' ends of the viral DNA are joined to the host DNA. We have examined the stereospecificity of human immunodeficiency virus type 1 integrase for phosphorothioate substrates in these reactions and in a third reaction, disintegration, which is macroscopically the reverse of integration. Integrase preferentially catalyzed end processing and integration of a substrate with the (R(p))-phosphorothioate stereoisomer at the reaction center and disintegration of a substrate with an (S(p))-phosphorothiate at the reaction center. These results suggest a model for the architecture of the active site of integrase, and its interactions with key features of the viral and target DNA.
逆转录病毒整合酶催化两个连续的化学反应，这两个反应对于将逆转录病毒基因组整合到宿主染色体中至关重要：3' 端加工，即从病毒 DNA 的每个 3' 端切割一个二核苷酸；以及整合反应本身，即病毒 DNA 产生的凹陷 3' 端与宿主 DNA 连接。我们已经研究了1型人类免疫缺陷病毒整合酶在这些反应以及第三个反应（解整合，从宏观上看它是整合的逆反应）中对硫代磷酸酯底物的立体特异性。整合酶优先催化在反应中心具有 (R(p))-硫代磷酸酯立体异构体的底物的末端加工和整合，以及在反应中心具有 (S(p))-硫代磷酸酯的底物的解整合。这些结果提示了一个关于整合酶活性位点结构及其与病毒和靶 DNA 关键特征相互作用的模型。
