Differences between mitochondrial and cytoplasmic transfer RNA and aminoacyl transfer RNA synthetases from rat liver.

Differences between mitochondrial and cytoplasmic transfer RNA and aminoacyl transfer RNA synthetases from rat liver.

The mitochondria of yeast,1 Neurospora,2 and Tetrahymena3 have been shown to contain transfer RNA (tRNA). Barnett et al.4 have found, in addition, that Neurospora mitochondria contain 15 aminoacyl-tRNA synthetases, at least three of which acylate only mitochondrial tRNA. The purpose of this communication is twofold. First we will present evidence showing that, as with eukaryotic microbial syste...

More evidence for a particle character of aminoacyl-transfer RNA synthetases isolated from rat liver.

Mitochondrial-specific aminoacyl-RNA synthetases.

Numerous lines of evidencel'indicate that protein synthesis occurs within mitochondria, and tRNA8, 15, 16 and aminoacyl-RNA synthetases8 have been prepared from these organelles. More recently, two very interesting aspects of mitochondrial protein synthesis have been described: (a) Although amino acid incorporation by yeast cytoplasmic ribosomal systems is not inhibited by chloramphenicol,'7 pr...

Aminoacyl synthetases and isoaccepting transfer RNA's from normal and regenerating rat liver.

made for 15 of the common 20 amino acids. An understanding of these changes aids in interpreting phenomena that may play a regulatory role in protein synthesis in rat liver regeneration. Under conditions of maximal acylation, aminoacyl synthetase activities change during regeneration, but not synchronously. By contrast, the tRNA composition of the effective tRNA pool remains constant. That is, ...

Base composition differences between avian myeloblastosis virus transfer RNA and transfer RNA isolated from host cells.

Using a novel chemical tritium derivative method, we have determined the base composition of 4S RNA isolated from an RNA tumor virus, the avian myeloblastosis virus, and from normal and neoplastic host cells. Extensive differences were detected, particularly with respect to the amount of methylated bases in the viral RNA. The viral 4S RNA, which fulfills the criteria for designation as transfer...