Molecular basis for drug- and peptide-dependent translational arrest

• Applicant: Professor Dr. Daniel Nicodemus Wilson
• Subject Area: Biochemistry ; Structural Biology
• Term: from 2014 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 262248213

During protein synthesis, nascent polypeptide chains can modulate the efficiency of translation. In bacteria, nascent polypeptide-mediated ribosome stalling during translation of leader peptides is used to induce expression of downstream genes, for example, Erm leader peptides modulate activity of the downstream erm genes that confer resistance to erythromycin and other clinically-important macrolide antibiotics. The programmed ribosome stalling required for induction of erm gene expression occurs when the macrolide antibiotic binds in the exit tunnel of the ribosome and cooperates with the nascent leader peptide to impair ribosomal function. The absence of any structures of drug-dependent stalled ribosome complexes has limited our mechanistic understanding of these regulatory processes. We have recently developed a procedure to generate drug-dependent stalled ribosome complexes that are suitable for structural interrogation. The aim of this proposal is to determine high resolution structures of a diverse array of drug-dependent stalled ribosome complexes. Such structures will provide much needed structural insight to elucidate how the drug and the nascent peptide cooperate to inhibit the peptide bond formation activity of the ribosome and thereby induce translation arrest. With the ever-increasing problem of multi-drug resistance in pathogenic bacteria, insight gained from investigating the drug-dependent resistance gene induction systems described here will be important for the future development of novel antimicrobial agents. Moreover, such studies will also establish a conceptual framework for understanding other cofactor- and peptide-dependent ribosome stalling systems.

• DFG Programme: Research Grants