对 HIV 在人类细胞中的复制来说， HIV 必须将其单股 RNA 的基因组转化成为可以整合至宿主基因组中的双股 DNA 。这一复杂的过程需要有数种酶的活性，其中包括涉及 DNA 合成、 RNA- DNA 复制中间产物中 RNA 链的降解、核酸链的置换以移除剩下的 RNA 及 DNA 片断，使得第 2 条 DNA 链得以合成以及核酸链的转移使得新合成的 DNA 可以在模版内或模版间移动等酶的活性。不同寻常的事，所有这些任务都是由一种单一的酶来进行的： HIV 逆转录酶（ RT ）。
在 2008 年 11 月 14 日 《科学》杂志的一篇 Report 中， Liu 等人为人们就 RT 是如何在其多种功能之间变换的提供了新的见解。应用 荧光共振能量转移的方法，该研究团队对个体 RT 分子与核酸底物之间的相互作用进行了实时的监控。 他们发现，这种酶在双股核酸之间滑行了长距离，并在相反的两个端点之间进行快速的穿梭行动。另外，它还能够在支持不同酶活性的相反的结合方位之间自动地翻转。由于 RT 是抗 HIV 疗法中的一个主要的标靶，对这种酶的更深的了解会对未来的药物设计有所助益。（生物谷Bioon.com）
生物谷推荐原始出处：
Science 14 November 2008: DOI: 10.1126/science.1163108
Slide into Action: Dynamic Shuttling of HIV Reverse Transcriptase on Nucleic Acid Substrates
Shixin Liu,1 Elio A. Abbondanzieri,1 Jason W. Rausch,4 Stuart F. J. Le Grice,4 Xiaowei Zhuang1,2,3*
The reverse transcriptase (RT) of human immunodeficiency virus (HIV) catalyzes a series of reactions to convert single-stranded viral RNA into double-stranded DNA for host cell integration. This process requires a variety of enzymatic activities, including DNA polymerization, RNA cleavage, strand transfer, and strand displacement synthesis. We used single-molecule fluorescence resonance energy transfer to probe the interactions between RT and nucleic acid substrates in real time. RT was observed to slide on nucleic acid duplexes, rapidly shuttling between opposite termini of the duplex. Upon reaching the DNA 3' terminus, RT can spontaneously flip into a polymerization orientation. Sliding kinetics were regulated by cognate nucleotides and anti-HIV drugs, which stabilized and destabilized the polymerization mode, respectively. These long-range translocation activities facilitate multiple stages of the reverse transcription pathway, including normal DNA polymerization and strand displacement synthesis.
1 Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.
2 Department of Physics, Harvard University, Cambridge, MA 02138, USA.
3 Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA.
4 HIV Drug Resistance Program, National Cancer Institute, Frederick, MD 21702, USA.
