During protein synthesis, a ribosome moves along the mRNA template and, using aminoacyl-tRNAs, decodes the template nucleotide triplets to assemble a protein amino acid sequence. This movement is accompanied by shifting of mRNA–tRNA complexes within the ribosome in a process called translocation. In living cells, this process proceeds in a unidirectional manner, bringing the ribosome to the 3′ end of mRNA, and is catalyzed by the GTPase translation elongation factor 2 (EF-G in prokaryotes and eEF2 in eukaryotes).
