FOR 967:  Functions and Mechanisms of Ribosomal Tunnel Exit Ligands (RTeLs)

• Subject Area: Biology
• Term: from 2008 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 50070218

Folding and intracellular transport of proteins are as essential for proper gene expression as transcription and translation. Ribosomes provide docking sites for proteins and protein complexes that interact to mediate the correct folding or transport of newly synthesised polypeptides. Typically, these factors bind near the ribosomal exit-site for nascent polypeptides (termed tunnel exit), located at the bottom of the large ribosomal subunit. Over the past several years, a number of these ribosomal ligands have been identified, and some were previously functionally and structurally characterised. Several of the principal investigators (Pls) of this Research Unit have made significant contributions in this field. Furthermore, the structural determinations of pro- and eukaryotic ribosomes during the past three years have facilitated the development of a variety of new approaches towards the function and dynamics of ribosome-ligand complexes.
The Research Unit intends to merge the established expertise of different Pls and employ them towards an in-depth understanding of the functions of various ligands of the ribosomal tunnel exit. It aims to elucidate central principles of co-translational folding, transport and covalent modification of proteins, down to the atomic level. Quantitative and dynamic aspects will be taken into account in this endeavour. In addition, mechanisms for regulation and coordination of the interactions will be characterised. Here, the Research Unit will use freely exchanged reagents in competition experiments. These studies should provide fundamental insights into the processes that generate functional three-dimensional structures of newly synthesised soluble and membrane proteins in the cytosol or endoplasmic reticulum of eukaryotes, as well as in bacteria and mitochondria. Thus, the Research Unit addresses a central and highly relevant topic of biochemistry and molecular cell biology.

• DFG Programme: Research Units

Projects

• Analyses of the dynamic interplay between ribosomes and bacterial translocon complexes (Applicant Koch, Hans-Georg )
• Analysis of the structure of the Oxa1-ribosome-complex by high-resolution cyro-electron microscopy (Applicants Beckmann, Roland ;  Herrmann, Johannes M. )
• Chaperone interactions with ribosome-bound nascent chains: Role in protein folding (Applicant Hartl, Franz-Ulrich )
• Coordination of the Research Unit 967 (Applicant Zimmermann, Richard )
• Functional analysis of enzymes involved in the co-translational modification of nascent chains (Applicant Bukau, Bernd )
• Functional characterization of the chaperone network connected to the eucaryotic ribosome (Applicant Rospert, Sabine Karola )
• Functional characterization of the ribosomal tunnel exit ligand ERj1 (Applicants Beckmann, Roland ;  Dudek, Johanna )
• Molecular analysis of Mdm38 function in mitochondrial protein expression (Applicant Rehling, Peter )
• Structural dynamics and regulation of the Sec61 complex (Applicants Wagner, Richard ;  Zimmermann, Richard )
• Structure and function of YidC and homologous membrane proteins (Applicant Sinning, Irmgard )

• Spokesperson: Professor Dr. Richard Zimmermann