Nagel Jord H A, Pleij Cornelis W A
Leiden Institute of Chemistry, Gorlaeus Laboratories, Einsteinweg 55, 2300 RA Leiden, The Netherlands.
Biochimie. 2002 Sep;84(9):913-23. doi: 10.1016/s0300-9084(02)01448-7.
Many biologically active RNAs show a switch in their secondary structure, which is accompanied by changes in their function. Such changes in secondary structure often require trans-acting factors, e.g. RNA chaperones. However, several biologically active RNAs do not require trans-acting factors for this structural switch, which is therefore indicated here as a "self-induced switch". These self-induced structural switches have several characteristics in common. They all start from a metastable structure, which is maintained for some time allowing or blocking a particular function of the RNA. Hereafter, a structural element becomes available, e.g. during transcription, triggering a rapid transition into a stable conformation, which again is accompanied by either a gain or loss of function. A further common element of this type of switches is the involvement of a branch migration or strand displacement reaction, which lowers the energy barrier of the reaction sufficiently to allow rapid refolding. Here, we review a number of these self-induced switches in RNA secondary structure as proposed for several systems. A general model for this type of switches is presented, showing its importance in the biology of functionally active RNAs.
许多具有生物活性的RNA在二级结构上会发生转变，同时其功能也会发生变化。二级结构的这种变化通常需要反式作用因子，例如RNA伴侣。然而，一些具有生物活性的RNA在这种结构转变过程中并不需要反式作用因子，因此这里将其称为“自我诱导转变”。这些自我诱导的结构转变具有几个共同特征。它们都起始于一个亚稳结构，该结构会维持一段时间，从而允许或阻断RNA的特定功能。此后，例如在转录过程中，一个结构元件变得可用，引发快速转变为稳定构象，这同样伴随着功能的获得或丧失。这类转变的另一个共同要素是涉及分支迁移或链置换反应，这会充分降低反应的能量屏障，以允许快速重新折叠。在此，我们综述了针对几个系统提出的一些RNA二级结构中的自我诱导转变。提出了这类转变的通用模型，展示了其在功能活性RNA生物学中的重要性。
