Promotes mitochondrial protein synthesis. May act as a fidelity factor of the translation reaction, by catalyzing a one-codon backward translocation of tRNAs on improperly translocated ribosomes. Binds to mitochondrial ribosomes in a GTP-dependent manner. GTP + H2O = GDP + H(+) + phosphate Present with 1890 molecules/cell in log phase SD medium. This protein may be expected to contain an N-terminal transit peptide but none has been predicted. Belongs to the TRAFAC class translation factor GTPase superfamily. Classic translation factor GTPase family. LepA subfamily.