FACTORS INFLUENCING GENETIC TRANSCRIPTION INITIATION AND TERMINATION

影响基因转录起始和终止的因素

• 批准号: 2575597
• 负责人: R J CROUCH
• 金额: --
• 依托单位: EUNICE KENNEDY SHRIVER NATIONAL INSTITUTE OF CHILD HEALTH & HUMAN DEVELOPMENT
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/2575597
• 关键词: Escherichia coli; bacterial genetics; bacterial proteins; genetic transcription; human immunodeficiency virus; microorganism culture; murine leukemia virus; protein structure function; ribonuclease H; transposon /insertion element; virus genetics; virus protein; virus replication

Ribonuclease H of reverse transcriptase and cellular RNases H are related proteins, both structurally and enzymatically. However, they differ in several aspects. Experiments designed to determine the sequences and structures that contribute to the differences between the two types of RNases H have been a focus of some of our project. We have expressed the RNase H domains of HIV and MuLV as separate proteins and studied some of its properties related to binding to RNA-DNA hybrids. E. coli RNase HI is more than 1,000 times as active enzymatically as either of the RNases H derived from the mammalian retroviruses. E. coli RNase HI binds very rapidly to RNA-DNA hybrids as does the MuLV RNase H. Thus, the differences in specific activity between these two enzymes is due to a difference in catalytic activity. In contrast, an E. coli RNase H protein deleted for the region known to be responsible interacting with RNA-DNA substrates (making it similar to HIV RNase H) binds very poorly to its substrate. When we target E. coli RNase H to mammalian retroviruses and yeast retrotransposons, differences in enzymatic properties result in inhibition of viral multiplication for MuLV, TY-1 and possibly HIV. Thus, targeting of cellular RNase H to virus particles may be a useful method for containing retroviral infections.

逆转录酶的核糖核酸酶 H 与细胞 RNases H 相关 蛋白质，无论是结构上的还是酶学上的。 然而，它们的不同之处在于 几个方面。 旨在确定序列和 导致两种类型之间差异的结构 RNases H 一直是我们一些项目的重点。 我们已经表达了 HIV 和 MuLV 的 RNase H 结构域作为单独的蛋白质，并研究了一些 其特性与 RNA-DNA 杂交体的结合有关。 大肠杆菌 RNase HI 酶活性是任一 RNase 的 1,000 倍以上 H源自哺乳动物逆转录病毒。 大肠杆菌 RNase HI 结合非常 像 MuLV RNase H 一样快速形成 RNA-DNA 杂交体。 这两种酶之间比活性的差异是由于 催化活性的差异。 相比之下，大肠杆菌 RNase H 已知负责相互作用的区域的蛋白质被删除 RNA-DNA 底物（使其类似于 HIV RNase H）结合非常差 到其基底。 当我们将大肠杆菌 RNase H 靶向哺乳动物时 逆转录病毒和酵母逆转录转座子，酶促差异 特性导致 MuLV、TY-1 病毒增殖受到抑制 可能还有艾滋病毒。 因此，将细胞 RNase H 靶向病毒颗粒 可能是遏制逆转录病毒感染的有用方法。