Structure and function of ribosomal protein-RNA complexes

In the frame of previous projects funded by the Austrian Science Fund (FWF), research was focusing on the regulation of synthesis of ribosomal proteins in archaea (formerly archaebacteria) and the interaction of these proteins with their specific binding sites on rRNA and mRNA. We could demonstrate that the affinity of ribosomal proteins L1, S8 and L10/L12(4) from (hyper)thermophilic archaea and bacteria for their specific rRNA target sites is 10 to 100fold higher compared to their conterparts from closely related mesophilic species. In the frame of this new project we will continue our investigations on ribosomal protein-rRNA and mRNA complexes. Reserch will concentrate on the following topics: - crystallization of L10/L12(4) in complex with the 23S rRNA target site from an archaeon and a bacterium to solve the structure (in collaboration with a Russian group) to fill the last major gap in the atomic structure of the ribosome. - crystallization (and solution of the structure) of a regulatory L1-mRNA complex from the archaeon Methanococcus as a major step - together with other experimental approaches - to solve the mechanism of this novel type of translational feedback inhibition. - identification of the structural elements (amino acid residues) that define proteins S8 and L1 as high or low affinity binders. To this end we will perform a stepwise conversion of the high-affinity binding proteins to low affinity binders. Furthermore, we will identify the amino acid residues in L1 that determine the specificity for the 23S rRNA and mRNA target sites. - investigation of the role of ribosomal proteins L1, S8 and L10/L12(4), respectively, that bind with very high affinity, on ribosomal functions. To this end we will construct hybrid ribosomes consisting of E. coli core subunits containing the high affinity binders. The combination of structural and functional data will provide insight, by which stratagies RNA binding proteins modulate their affinities for their specific RNA binding sites.

In the frame of previous projects funded by the Austrian Science Fund (FWF), research was focusing on the regulation of synthesis of ribosomal proteins in archaea (formerly archaebacteria) and the interaction of these proteins with their specific binding sites on rRNA and mRNA. We could demonstrate that the affinity of ribosomal proteins L1, S8 and L10/L12(4) from (hyper)thermophilic archaea and bacteria for their specific rRNA target sites is 10 to 100fold higher compared to their conterparts from closely related mesophilic species. In the frame of this new project we will continue our investigations on ribosomal protein-rRNA and mRNA complexes. Reserch will concentrate on the following topics: crystallization of L10/L12(4) in complex with the 23S rRNA target site from an archaeon and a bacterium to solve the structure (in collaboration with a Russian group) to fill the last major gap in the atomic structure of the ribosome. crystallization (and solution of the structure) of a regulatory L1-mRNA complex from the archaeon Methanococcus as a major step - together with other experimental approaches - to solve the mechanism of this novel type of translational feedback inhibition. identification of the structural elements (amino acid residues) that define proteins S8 and L1 as high or low affinity binders. To this end we will perform a stepwise conversion of the high-affinity binding proteins to low affinity binders. Furthermore, we will identify the amino acid residues in L1 that determine the specificity for the 23S rRNA and mRNA target sites. investigation of the role of ribosomal proteins L1, S8 and L10/L12(4), respectively, that bind with very high affinity, on ribosomal functions. To this end we will construct hybrid ribosomes consisting of E. coli core subunits containing the high affinity binders. The combination of structural and functional data will provide insight, by which stratagies RNA binding proteins modulate their affinities for their specific RNA binding sites.