Structural asymmetry in the eukaryotic Elongator complex.

Nucleoside modifications in tRNA anticodons regulate ribosome dynamics during translation elongation and, thereby, fine-tune global protein synthesis rates. The highly conserved eukaryotic Elongator complex conducts specific C5-substitutions in tRNA wobble base uridines. It harbors two copies of each of its six individual subunits, which are all equally important for its activity. Here, we summarize recent developments focusing on the architecture of the Elongator complex, showing an asymmetric subunit arrangement, and its functional implications. In addition, we discuss the role of its proposed active site, its individual subunits and temporarily associated regulatory factors. Finally, we aim to provide mechanistic explanations for the link between mutations in Elongator subunits and the onset of several severe human pathologies.