22] Bovine mitochondrial ribosomes

Abstract

Publisher Summary The bovine mitochondrial ribosome is being developed as a model system for studying the structure and function of mammalian mitochondrial ribosomes. These 55 S ribosomes from mammalian mitochondria resemble bacterial and eukaryotic cytoplasmic ribosomes in general functional properties, but in terms of composition, fine structure, and physicochemical properties, they differ unexpectedly from both of those kinds of ribosomes, and from other kinds of mitochondrial ribosomes. Products of two genomes, mammalian mitochondrial ribosomes are considered to be members of the prokaryotic class, because they have more homologies with bacterial ribosomes than with eukaryotic cytoplasmic ribosomes. The unusual properties of these ribosomes raise questions about their relation to other kinds of ribosomes, and their large number of proteins raises questions about their functional and structural organization, and about the identity of individual mitoribosomal proteins that are homologous to proteins in other ribosomes.