Riboswitches: emerging themes in RNA structure and function.
Riboswitches are RNAs capable of binding cellular metabolites using a diverse array of secondary and tertiary structures to modulate gene expression. The recent determination of the three-dimensional structures of parts of six different riboswitches illuminates common features that allow riboswitches to be grouped into one of two types. Type I riboswitches, as exemplified by the purine riboswitch, are characterized by a single, localized binding pocket supported by a largely pre-established global fold. This arrangement limits ligand-induced conformational changes in the RNA to a small region. In contrast, Type II riboswitches, such as the thiamine pyrophosphate riboswitch, contain binding pockets split into at least two spatially distinct sites. As a result, binding induces both local changes to the binding pocket and global architecture. Similar organizational themes are found in other noncoding RNAs, making it possible to begin to build a hierarchical classification of RNA structure based on the spatial organization of their active sites and associated secondary structural elements.
Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, USA.
Rebecca K
RK
Montange
Robert T
RT
Batey
D015870:Gene Expression / Q000502:physiology*; D005786:Gene Expression Regulation / Q000502:physiology*; D008956:Models, Chemical; D008957:Models, Genetic; D008958:Models, Molecular; D012313:RNA / Q000737:chemistry / Q000502:physiology / Q000648:ultrastructure; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000502:physiology / Q000648:ultrastructure; D013329:Structure-Activity Relationship
D016601:RNA-Binding Proteins; D012313:RNA