Mitochondria: Unusual features of the mammalian mitoribosome.
Mitochondria are responsible for generating most of the energy required by the cell. The oxidative phosphorylation (OXPHOS) system that produces the energy is composed of nuclear and mitochondrial encoded polypeptides. The 13 polypeptides encoded by the mitochondrial genome are synthesized by mitochondrial ribosomes (mitoribosomes). The evolutionary divergence of mitoribosomes has seen a reduction in their rRNA content and an increase in ribosomal proteins compared to their bacterial and cytoplasmic counterparts. Recent advances in cryo-electron microscopy (cryo-EM) mapping have revealed not all of these proteins simply replace the roles of the rRNA and that many have new roles. The mitoribosome has unique features that include a gatelike structure at the mRNA entrance that may facilitate recruitment of leaderless mitochondrial mRNAs and also a polypeptide exit tunnel that has an unusual nascent-polypeptide exit mechanism. Defects in the mitochondrial translation machinery are a common contributor to multi-system disorders known as mitochondrial diseases for which currently there are no cures or effective treatments.
Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, Western Australia 6009, Australia.
Tara R
TR
Richman
Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, Western Australia 6009, Australia; School of Chemistry and Biochemistry, The University of Western Australia, Crawley, Western Australia 6009, Australia.
Oliver
O
Rackham
Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, Western Australia 6009, Australia; School of Chemistry and Biochemistry, The University of Western Australia, Crawley, Western Australia 6009, Australia. Electronic address: aleksandra.filipovska@uwa.edu.au.
Aleksandra
A
Filipovska
D000818:Animals; D020459:Genes, rRNA; D054629:Genome, Mitochondrial; D006801:Humans; D008928:Mitochondria / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D028361:Mitochondrial Diseases / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D024101:Mitochondrial Proteins / Q000235:genetics* / Q000378:metabolism; D010085:Oxidative Phosphorylation; D010455:Peptides / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D012270:Ribosomes / Q000235:genetics* / Q000378:metabolism
D024101:Mitochondrial Proteins; D010455:Peptides; D012333:RNA, Messenger
Mitochondria; Mitochondrial disease; Mitoribosome; Polypeptide exit tunnel; mRNA entrance site