Practice question

In prokaryotes, elongation factor Tu, historically called unstable factor, functions as a GTPase escort for aminoacyl-tRNA. EF-Tu-GTP forms a high-affinity ternary complex with aa-tRNA, protecting its labile ester bond and delivering it to the decoding center in the ribosomal A-site. Codon-anticodon matching in the decoding center triggers GTP hydrolysis, causing conformational change, dissociation of EF-Tu-GDP, and accommodation of the tRNA acceptor end into the peptidyl transferase center for peptide bond formation. EF-Ts serves as guanine nucleotide exchange factor regenerating EF-Tu-GTP. This coupled delivery and proofreading step ensures rapid and accurate elongation selection.