Schauer M, Billich A
Sandoz Research Institute, Department of Antiretroviral Therapy, Vienna, Austria.
Biochem Biophys Res Commun. 1992 Jun 30;185(3):874-80. doi: 10.1016/0006-291x(92)91708-x.
HIV-1 integrase binds to both double- and single-stranded DNA with Kd-values of around 20 nM, irrespective of sequence similarities with the termini of the viral LTR. For integration activity, however, the correct LTR sequence of the substrate is required. The putative zinc-binding site present at the N-terminus of the protein is not essential for DNA binding, since deletion mutants of the protein lacking this sequence show similar affinity towards DNA as the wild-type; however, these mutants are not capable of performing the LTR-cleavage and integration reactions. Thus, it appears that the N-terminal part of the integrase is essential for catalytic activity.
HIV-1整合酶与双链和单链DNA均能结合，解离常数（Kd值）约为20 nM，与病毒长末端重复序列（LTR）末端的序列相似性无关。然而，对于整合活性而言，底物需要正确的LTR序列。该蛋白质N端存在的假定锌结合位点对于DNA结合并非必需，因为缺失该序列的蛋白质缺失突变体对DNA的亲和力与野生型相似；然而，这些突变体无法进行LTR切割和整合反应。因此，整合酶的N端部分对于催化活性似乎至关重要。
