Involved in regulation of mitochondrial protein translation and respiration. Plays a role in mitochondria-mediated cell death. May act as a scaffolding protein or stabilizer of respiratory chain supercomplexes. Binds GTP. Homodimer or multimer. Interacts with mitochondrial complex I, DAP3, MRPL12 and MRPS27. Expressed in tissues associated with high mitochondria content including testes, heart, liver, brain and thymus. Also expressed in various bone cell lines. At 10.5 dpc, weak but widespread expression. By 12.5 dpc prominently expressed in the liver and also detected in developing CNS and dorsal root ganglia. At 14.5 dpc, expression is intensified in bone. Mice display mid-gestation lethality associated with a severe developmental defect of the embryo and trophoblast. Primary embryonic fibroblasts isolated from mutant 9.5 dpc embryos show deficient mitochondrial synthesis and a global defect of oxidative phosphorylation. Belongs to the TRAFAC class YlqF/YawG GTPase family. NOA1 subfamily.