title: Cell-free translation of mitochondrial nicotinamide nucleotide transhydrogenase.
abstract: Mammalian nicotinamide nucleotide transhydrogenase is translated as a 5000 daltons larger molecular weight precursor in a cell-free system programmed with rat liver polysomes. The mature rat liver enzyme had the same molecular weight as the purified beef heart enzyme, 115 000 daltons. The precursor was not processed in vitro by liver mitochondria or by a rat liver mitochondrial matrix fraction, nor did it appear to bind to mitochondria. In contrast, pre-FeS protein of the cytochrome bc1 complex was processed in the same samples by both mitochondria and matrix, suggesting an important difference in the processing mechanisms or in the efficiency of processing of the two precursors.
mesh_terms: D000818:Animals; D002417:Cattle; D002474:Cell-Free System; D004792:Enzyme Precursors / Q000096:biosynthesis*; D066298:In Vitro Techniques; D008930:Mitochondria, Liver / Q000378:metabolism*; D008970:Molecular Weight; D009247:NADH, NADPH Oxidoreductases / Q000096:biosynthesis*; D009250:NADP Transhydrogenases / Q000096:biosynthesis*; D014176:Protein Biosynthesis; D011499:Protein Processing, Post-Translational; D011817:Rabbits; D051381:Rats; D012156:Reticulocytes / Q000378:metabolism
chemical_list: D004792:Enzyme Precursors; D009247:NADH, NADPH Oxidoreductases; D009250:NADP Transhydrogenases