Mitochondrial GTPase that mediates the disassembly of ribosomes from messenger RNA at the termination of mitochondrial protein biosynthesis. Not involved in the GTP-dependent ribosomal translocation step during translation elongation (By similarity). Required for respiratory growth and essential for mitochondrial genome maintenance. Results in loss of mitochondrial DNA. Causes a significant slow growth phenotype under normal growth conditions (glucose) and a reduced chronological life-span (CLS). Growth on a non-fermentable carbon source (gylcerol) is absent. Present with 1733 molecules/cell in log phase SD medium. Belongs to the TRAFAC class translation factor GTPase superfamily. Classic translation factor GTPase family. EF-G/EF-2 subfamily.