MITOCHONDRIAL TRANSFER RIBONUCLEIC ACIDS

Abstract
Mitochondrial preparations from Neurospora crassa were examined for the presence of transfer RNA''s. Mitochondria contained tRNA for all 18 amino acids tested. One species of aspartic acid tRNA appeared to be uniquely associated with mitochondria rather than the cytoplasm. The mitochondrial tRNA fraction was greatly enriched for one of the species of phenylalanine tRNA. These tRNA''s appear to be an integral part of the mitochondrion since they are not susceptible to venom phosphodiesterase digestion prior to mitochondrial disruption, and isolated tRNA does not exhibit an affinity to bind or to associate with the mitochondria under the conditions of their isolation.