title: Mammalian mitochondrial transfer RNAs: chromatographic properties, size and origin.
abstract: Incubation of isolated rat liver mitochondria with radioactive amino acids resulted in the charging of tRNAs for arginine, asparagine, leucine, lysine, methionine, proline and valine. The aminoacyl-tRNAs were shown to be distinct from their cytosolic counterparts by chromatography on RPC-5. By electrophoresis on urea polyacrylamide slab gels it was found that all these mitochondrial aminoacyl-tRNAs were about 70-76 nucleotides long. The unique mitochondrial asparaginyl- and prolyl-tRNAs, not previously identified in mammalian cells, were shown to hybridize to mtDNA. Mitochondrial leucyl-tRNA separated into 3 peaks on RPC-5 and the first species was shown to be different than a combination of the other two by molecular size and partial RNase T1 digestion patterns. Each was coded by a separate gene on mtDNA as shown by partial additivity of hybridization. Separate genes for mitochondrial tRNAMetm and tRNAMetf, separated by RPC-5 chromatography, were also demonstrated. These results bring to 21 the number of individual tRNAs coded by mammalian mtDNA.
mesh_terms: D000818:Animals; D003600:Cytosol / Q000032:analysis; D008099:Liver / Q000032:analysis; D008930:Mitochondria, Liver / Q000378:metabolism*; D008970:Molecular Weight; D009693:Nucleic Acid Hybridization; D014176:Protein Biosynthesis; D012343:RNA, Transfer / Q000302:isolation & purification / Q000378:metabolism; D051381:Rats
chemical_list: D012343:RNA, Transfer