The ribosome is an essential ribonucleoprotein enzyme, and its biogenesis is a fundamental process in all living cells. Recent X-ray crystal structures of the bacterial ribosome and new technologies have allowed a greater interrogation of in vitro ribosome assembly; however, substantially less is known about ribosome biogenesis in vivo. Ongoing investigations are focused on elucidating the cell...

Ribosome profiling provides a snapshot of ribosome positions and density across the transcriptome at a sub-codon resolution. By sequencing the entire set of ribosome-protected mRNA fragments, this powerful approach has been successfully used to measure ribosome dynamics and reveal the hidden coding potential of transcriptome. Since its conceptual inception, ribosome profiling has evolved into a...

.......................................................................................... 5 SAMMANFATTNING PÅ SVENSKA ............................................... 7 PAPERS IN THIS THESIS .................................................................. 9 THE RIBOSOME ............................................................................... 10 The coordinated assembly of a ribosome .....

tmRNA and SmpB are the main participants of trans-translation, a process which rescues the ribosome blocked during translation of non-stop mRNA. While a one-to-one stoichiometry of tmRNA to the ribosome is generally accepted, the number of SmpB molecules in the complex is still under question. We have isolated tmRNA-ribosome complexes blocked at different steps of the tmRNA path through the rib...

'Ribosome scanning' is the generally accepted mechanism for explaining how a ribosome finds an initiation codon located far removed from the ribosome recruiting site (cap structure). However, the molecular characteristics of ribosome scanning along 5' untranslated regions (UTRs) remain obscure. Herein, using a rabbit reticulocyte lysate (RRL) system and artificial ribonucleic acid (RNA) constru...

The universally conserved GTPase elongation factor G (EF-G) catalyzes the translocation of tRNA and mRNA on the ribosome after peptide bond formation. Despite numerous studies suggesting that EF-G undergoes extensive conformational rearrangements during translocation, high-resolution structures exist for essentially only one conformation of EF-G in complex with the ribosome. Here, we report fou...