although the e. coli and yeast mitochondrial aminoacyl-trna synthetases are sufficiently similar in their primary sequences to suggest a common evolutionary origin , they have undergone significant changes as evidenced by the low homology in some regions of the polypeptide chains and the presence in the mitochondrial enzyme of two domains that are lacking in the bacterial phenylalanyl-trna synthetase .
C0002529
aminoacyl-trna synthetases
C0031460
phenylalanyl-trna synthetase