Cryo-Em structure of an endogenous late pre-40S ribosomal subunit

Eukaryotic ribosome biogenesis is a complex process that requires the concerted activity of numerous assembly factors. These factors orchestrate the assembly process by forming transient interactions with evolving ribosomal subunits, forming a series of temporally and spatially distinct pre-ribosomal particles. I will present the cryo-EM structure of a late pre-40S particle from Saccharomyces cerevisiae at 3.6Å resolution, that provides insight into the role of several 40S assembly factors. Whilst associated, these factors would appear to prevent the maturation of functionally important regions of the small subunit, including the decoding centre. Thus, the association of these assembly factors keep the subunit in a translationally inactive state and we propose that their sequential removal may represent checkpoints in the maturation pathway. 

More on Dr Emma Thomson