Elongation steps

EF-Tu-GTP places the aminoacyl-tRNA on the ribosome and then is released as EF-Tu-GDP. EF-Ts is required to mediate the replacement of GDP by GTP. The reaction consumes GTP and releases GDP. The only aminoacyl-tRNA that cannot be recognised by EF-Tu-GTP is fMet-tRNAf, preventing use internally