G-protein that, in its active GTP-bound form, binds to and delivers aminoacyl-tRNA to the A-site of ribosomes during protein biosynthesis. In the presence of a correct codon-anticodon match between the aminoacyl-tRNA and the A-site codon of the ribosome-bound mRNA, the ribosome acts as a GTPase activator and the GTP is hydrolyzed. The inactive GDP-bound form leaves the ribosome and must be recycled before binding another molecule of aminoacyl-tRNA. Required for mitochondrial protein biosynthesis and maintenance of mitochondrial DNA. Protein biosynthesis; polypeptide chain elongation. The precursor is processed in two steps involving mitochondrial intermediate peptidase (MIP) and mitochondrial processing peptidase (MPP). Present with 58527 molecules/cell in log phase SD medium. Belongs to the TRAFAC class translation factor GTPase superfamily. Classic translation factor GTPase family. EF-Tu/EF-1A subfamily.