School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA.
Nucleic Acids Res. 2011 Jan;39(1):300-12. doi: 10.1093/nar/gkq761. Epub 2010 Sep 7.
Several important viruses including the human immunodeficiency virus type 1 (HIV-1) and the SARS-associated Coronavirus (SARS-CoV) employ programmed -1 ribosomal frameshifting (PRF) for their protein expression. Here, a kinetic framework is developed to describe -1 PRF. The model reveals three kinetic pathways to -1 PRF that yield two possible frameshift products: those incorporating zero frame encoded A-site tRNAs in the recoding site, and products incorporating -1 frame encoded A-site tRNAs. Using known kinetic rate constants, the individual contributions of different steps of the translation elongation cycle to -1 PRF and the ratio between two types of frameshift products were evaluated. A dual fluorescence reporter was employed in Escherichia coli to empirically test the model. Additionally, the study applied a novel mass spectrometry approach to quantify the ratios of the two frameshift products. A more detailed understanding of the mechanisms underlying -1 PRF may provide insight into developing antiviral therapeutics.
几种重要的病毒，包括人类免疫缺陷病毒 1 型（HIV-1）和严重急性呼吸综合征相关冠状病毒（SARS-CoV），在其蛋白表达过程中采用了 -1 核糖体移码（PRF）。这里开发了一个动力学框架来描述 -1 PRF。该模型揭示了三种导致两种可能的移码产物的 -1 PRF 动力学途径：那些在重编码位点掺入零框编码的 A 位 tRNA 的产物，以及掺入 -1 框编码的 A 位 tRNA 的产物。利用已知的动力学速率常数，评估了翻译延伸循环的不同步骤对 -1 PRF 的贡献以及两种移码产物的比例。该研究在大肠杆菌中使用双荧光报告基因来对模型进行了经验测试。此外，该研究应用了一种新的质谱方法来定量两种移码产物的比例。更深入地了解 -1 PRF 的机制可能为开发抗病毒治疗方法提供思路。
