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科罗拉多大学医学院的研究人员解释在某些病毒中发现RNA分子如何模拟其他分子形状作为一项策略“劫持”细胞制造更多病毒。 |
科罗拉多大学医学院的研究人员解释在某些病毒中发现RNA分子如何模拟其他分子形状作为一项策略“劫持”细胞制造更多病毒。病毒是健康和农业的全球威胁。为了繁殖，病毒感染细胞并占据细胞的生化机制。因此了解病毒征服细胞利用的基本分子过程是重要的。文章发表在《Nature》期刊上。
由医学院的生物化学和分子遗传学副教授兼霍华德休斯医学研究所早期职业科学家Jeffrey S. Kieft博士与他的同事解答了已经困扰科学家几十年的一个机制和分子秘密。
病毒是全世界健康和农业的威胁。为了繁殖，病毒感染细胞并占据细胞的生化机制。因此了解病毒征服细胞利用的基本分子过程是重要的。在这些过程中是病毒创建分子的能力‘模拟’细胞分子的结构和行为。病毒的分子‘特洛伊木马’是它们接管细胞策略的一部分。
文中描述一个病毒RNA的三维结构模拟一种细胞中发现的最丰富的RNAs。这种病毒RNA是一种分子模仿者。然而，这种RNA如何充当一个模仿者，它是如何在不同的结构之间转化，而有时如何完成复杂工作还是一个谜。
利用一种称为x射线衍射晶体分析法的技术，Kieft 及其同事使得高分辨率的分子复杂三维结构可视化。它们发现病毒RNA有一个‘两面派’体系结构：一面是细胞RNA的模拟，另一面是完全不同的，这很可能提供能力在感染期间完成一些工作。这种行为模式也许是普遍的，因此这项研究能适用于许多不同的病毒。
对病毒RNA能模仿其他分子作为其‘劫持’细胞策略的一分部的了解也许有助于科学家开发抗感染性疾病的治疗或疫苗。(来源：生物帮)
原文摘要：
The structural basis of transfer RNA mimicry and conformational plasticity by a viral RNA
Timothy M. Colussi,David A. Costantino,John A. Hammond,Grant M. Ruehle,Jay C. Nix & Jeffrey S. Kieft
RNA is arguably the most functionally diverse biological macromolecule. In some cases a single discrete RNA sequence performs multiple roles, and this can be conferred by a complex three-dimensional structure. Such multifunctionality can also be driven or enhanced by the ability of a given RNA to assume different conformational (and therefore functional) states1. Despite its biological importance, a detailed structural understanding of the paradigm of RNA structure-driven multifunctionality is lacking. To address this gap it is useful to study examples from single-stranded positive-sense RNA viruses, a prototype being the tRNA-like structure (TLS) found at the 3′ end of the turnip yellow mosaic virus (TYMV). This TLS not only acts like a tRNA to drive aminoacylation of the viral genomic (g)RNA2, 3, 4, but also interacts with other structures in the 3′ untranslated region of the gRNA5, contains the promoter for negative-strand synthesis, and influences several infection-critical processes6. TLS RNA can provide a glimpse into the structural basis of RNA multifunctionality and plasticity, but for decades its high-resolution structure has remained elusive. Here we present the crystal structure of the complete TYMV TLS to 2.0?? resolution. Globally, the RNA adopts a shape that mimics tRNA, but it uses a very different set of intramolecular interactions to achieve this shape. These interactions also allow the TLS to readily switch conformations. In addition, the TLS structure is ‘two faced’: one face closely mimics tRNA and drives aminoacylation, the other face diverges from tRNA and enables additional functionality. The TLS is thus structured to perform several functions and interact with diverse binding partners, and we demonstrate its ability to specifically bind to ribosomes.
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