MECHANISM OF RECOMBINATION BY HIV REVERSE TRANSCRIPTASE

HIV逆转录酶的重组机制

基本信息

批准号：
6627193
负责人：
JEFFREY J DESTEFANO
金额：
$ 20.43万
依托单位：
UNIV OF MARYLAND, COLLEGE PARK
依托单位国家：
美国
项目类别：
财政年份：
1994
资助国家：
美国
起止时间：
1994-05-01 至 2004-03-31
项目状态：
已结题

项目摘要

The human immunodeficiency virus (HIV), the Causative agent of Acquired Immune Deficiency Syndrome (AIDS), has been responsible for the deaths of millions of people in the last two decades. Attempts to combat HIV have been hampered due to the viruses ability to rapidly mutate and produce genetic variants that can circumvent the immune response and resist drug therapy. Recombination, which occurs by a process referred to as strand transfer, is an important mechanisms used by HIV to increase diversity. Two viral proteins, reverse transcriptase (RT) and nucleocapsid (NC) have been clearly implicated in recombination. The goal of this proposal is to answer key questions regarding the mechanism of recombination and the interaction of RT with nucleic acids. This will be accomplished by investigating 4 specific aims related directly to recombination: (1) Analysis of strand transfer "hotspots" that promote recombination events, (2) Defining the role of RT-directed base misincorporations in inducing recOmbination (strand transfer) events, (3) Analysis of RT binding and cleavage on structures mimicking replication or strand transfer intermediates, and (4) Probing the mechanism by which NC catalyzes strand-exchange to promote strand transfer. The goal of the first aim is to determine why particular sites promote transfer while others do not. A potential link between two of the major mechanisms for the generation of HIV mutants will be explored in the second aim while specific interactions between key viral proteins and unique strand transfer intermediates are studied in aims 3 and 4. The basic interaction of RT with nucleic acids will be investigated through 3 specific aims: (1) Quantitative assessment of the interaction of RT with nucleic acid substrates under physiological conditions, (2) Determining the role of different regions of RT in binding to nucleic acid using chimeric substrates, and (3) Searching for nucleic acids sequences that can bind RT with high affinity. The basic goal of these studies is to define RT and nucleic acid properties importantJor 'tight" binding between the two. Overall, the proposed experiments should help clarify some of the important unanswered questions and could also be important in developing and evaluating strategies to combat HIV. For example, an understanding of the interplay between RT fidelity and recombination could allow for better predictive models that help determine how therapy will impact HIV evolution. Perhaps drug combinations that tend to lead to a more or less accurate RT would be advantageous in the long run.

在过去的二十年中，人类免疫缺陷病毒（HIV）是获得免疫缺陷综合征（AIDS）的致病药物（AIDS）。由于病毒能够快速突变并产生可以避免免疫反应和抵抗药物治疗的遗传变异的病毒，试图对抗HIV的尝试受到了阻碍。重组是通过称为链转移的过程发生的，是艾滋病毒用于增加多样性的重要机制。两种病毒蛋白，逆转录酶（RT）和核素（NC）已明显与重组有关。该提案的目的是回答有关重组机制以及RT与核酸的相互作用的关键问题。这将通过研究与重组直接相关的4个特定目的来实现：（1）链链传递“热点”的分析，以促进重组事件，（2）定义RT指导的基础失调在诱导重新组合（Strand转移）事件中的作用，（3）（3）对RT的结合和对4的结构进行分析（3）模拟的结构，并模拟了Replication Intersiations（4催化链交换以促进链的转移。第一个目的的目的是确定为什么特定站点促进转移而其他站点不促进转移。 A potential link between two of the major mechanisms for the generation of HIV mutants will be explored in the second aim while specific interactions between key viral proteins and unique strand transfer intermediates are studied in aims 3 and 4. The basic interaction of RT with nucleic acids will be investigated through 3 specific aims: (1) Quantitative assessment of the interaction of RT with nucleic acid substrates under physiological conditions, (2) Determining the role of different使用嵌合底物与核酸结合的RT区域，以及（3）搜索可以与高亲和力结合RT的核酸序列。这些研究的基本目标是定义两者之间重要的rt和核酸特性“紧密”的结合。总的来说，提出的实验应有助于阐明一些重要的未解决的问题，并且在制定和评估策略以对抗HIV的策略也可能很重要。从长远来看，导致或多或少准确的RT将是有利的。