Research project P 14000 RNA chaperones Renée SCHROEDER 11.10.1999
The folding process of large RNA molecules is easily disturbed by the formation of alternative base pairs, slowing
down or completely inhibiting the formation of the active structure. It has been postulated, that proteins exist,
which aid in the folding process by resolving or impeding the formation of incorrect structures. These proteins,
termed RNA chaperones, are thought to be non-specific RNA-binding proteins, which do not recognize a specific
structure nor sequences. In vitro, three activities have been attributed to RNA chaperones: strand displacement,
strand annealing and acceleration of the association of ribozymes.
The current project proposal will investigate how these proteins function in vivo. We propose to use the pre-mRNA
of T4 phage derived thymidylate synthase (td) gene, which contains a self-splicing group I intron, whose folding is
dependent on RNA chaperone activity, to study the RNA chaperone activity of a large number of proteins. The
advantage of our system is the fact that the folding process of this pre-mRNA is significantly slowed down the
formation of an aberrant fold, which leads to splicing deficiency, a parameter -which is easier to measure than
folding. We just recently developed an in vivo assay to measure the RNA chaperone activity of proteins.
The aim of this project is to understand what RNA chaperones do to RNA structure in vivo, to find and to define
the protein motif, which is responsible for chaperone activity. We will develop a screen to search for proteins with
RNA chaperone activity from prokaryotes and eukaryotes. By constructing pre-mRNAs containing various
structural motifs, we will try to understand, what kind of RNA structures can be resolved. Additionaly, by
constructing folding traps of various stability, we. want to address thermodynamic properties of these proteins.