Translocation at work

Translocation is an essential step of protein synthesis in which the large tRNA2–mRNA complex inside the ribosome moves from the A and P sites to the P and E sites, respectively, bringing a new mRNA codon into the decoding center. This process is catalyzed by the elongation factor EF-G–GTP (eEF2 in eukaryotes) and is the least understood stage of peptide elongation. Four new reports describe the crystal structures of translocation intermediates, illustrating important details of the translocation reaction.