Lee Hak Sung, Kang Seung Yi, Shin Cha-Gyun
Department of Biotechnology and BET Research Institute, Chung-Ang University, Ansung 456-756, Korea.
Mol Cells. 2005 Apr 30;19(2):246-55.
Retroviral integrases insert viral DNA into target DNA. In this process they recognize their own DNA specifically via functional domains. In order to analyze these functional domains, we constructed six chimeric integrases by swapping domains between HIV-1 and HFV integrases, and two point mutants of HFV integrase. Chimeric integrases with the central domain of HIV-1 integrase had strand transfer and disintegration activities, in agreement with the idea that the central domain determines viral DNA specificity and has catalytic activity. On the other hand, chimeric integrases with the central domain of HFV integrase did not have any enzymatic activity apart from FFH that had weak disintegration activity, suggesting that the central domain of HFV integrase was defective catalytically or structurally. However, these inactive chimeras were efficiently complemented by the point mutants (D164A and E200A) of HFV integrase, indicating that the central domain of HFV integrase possesses potential enzymatic activity but is not able to recognize viral or target DNA without the help of its homologous N-terminal and C-terminal domains.
逆转录病毒整合酶将病毒DNA插入靶DNA中。在此过程中，它们通过功能结构域特异性识别自身DNA。为了分析这些功能结构域，我们通过在HIV-1整合酶和HFV整合酶之间交换结构域构建了六种嵌合整合酶，以及HFV整合酶的两种点突变体。具有HIV-1整合酶中央结构域的嵌合整合酶具有链转移和解离活性，这与中央结构域决定病毒DNA特异性并具有催化活性的观点一致。另一方面，具有HFV整合酶中央结构域的嵌合整合酶除了具有弱解离活性的FFH外没有任何酶活性，这表明HFV整合酶的中央结构域在催化或结构上存在缺陷。然而，这些无活性的嵌合体被HFV整合酶的点突变体（D164A和E200A）有效互补，这表明HFV整合酶的中央结构域具有潜在的酶活性，但在没有其同源N端和C端结构域帮助的情况下无法识别病毒或靶DNA。
