Figure 1.

Biogenesis of the mitoribosome. The mitoribosome is composed of mitoribosomal proteins (MRPs) and RNAs, which are produced in the cytosol and mitochondria, respectively. The RNA components are derived from the transcription of mtDNA in nucleoids, followed by the RNA maturation in RNA granules. MRPs are synthesized by the 80S cytosolic ribosome and imported into the mitochondrial matrix through the mitochondrial import machinery (TOM and TIM proteins). Next, MRPs and rRNAs are assembled into the mitochondrial large subunit (mt-LSU) and the mitochondrial small subunit (mt-SSU). The complete 55S monosome is anchored to the inner mitochondrial membrane (IMM) and interacts with the translocase OXA1L. OMM-outer mitochondrial membrane.