The structure of the yeast mitochondrial ribosome.
Mitochondria have specialized ribosomes (mitoribosomes) dedicated to the expression of the genetic information encoded by their genomes. Here, using electron cryomicroscopy, we have determined the structure of the 75-component yeast mitoribosome to an overall resolution of 3.3 angstroms. The mitoribosomal small subunit has been built de novo and includes 15S ribosomal RNA (rRNA) and 34 proteins, including 14 without homologs in the evolutionarily related bacterial ribosome. Yeast-specific rRNA and protein elements, including the acquisition of a putatively active enzyme, give the mitoribosome a distinct architecture compared to the mammalian mitoribosome. At an expanded messenger RNA channel exit, there is a binding platform for translational activators that regulate translation in yeast but not mammalian mitochondria. The structure provides insights into the evolution and species-specific specialization of mitochondrial translation.
MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.
Nirupa
N
Desai
MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.
Alan
A
Brown
MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.|SciLifeLab, Stockholm University, SE-106 91 Stockholm, Sweden.
Alexey
A
Amunts
MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK. ramak@mrc-lmb.cam.ac.uk.
V
V
Ramakrishnan
D000818:Animals; D020285:Cryoelectron Microscopy; D019143:Evolution, Molecular; D000069396:Mitochondrial Ribosomes / Q000737:chemistry* / Q000648:ultrastructure; D009690:Nucleic Acid Conformation; D014176:Protein Biosynthesis; D011487:Protein Conformation; D012333:RNA, Messenger / Q000737:chemistry / Q000648:ultrastructure; D012335:RNA, Ribosomal / Q000737:chemistry / Q000648:ultrastructure; D012441:Saccharomyces cerevisiae / Q000648:ultrastructure*
D012333:RNA, Messenger; D012335:RNA, Ribosomal