Proceedings of the National Academy of Sciences · 1991 · 60 citations · 28 references
Life SciencesBiochemistryMolecular BiologyEnzymologyMitochondrial BiologyMolecular EvolutionMitochondrial TranslationTranslation In EukaryotesAminoacyl-transfer Ribonucleic Acid Synthetase EvolutionAminoacyl-transfer Ribonucleic Acid Synthetase StructureAminoacyl-trna SynthetasesClass Ii Aminoacyl-transfer Ribonucleic Acid SynthetasesEscherichia ColiMitochondrial Aminoacyl-transfer Ribonucleic Acid SynthetasesQuaternary Structure ClassificationQuaternary Structure Determination
Phenylalanyl-tRNA synthetases [L-phenylalanine:tRNAPhe ligase (AMP-forming), EC 6.1.1.20] from Escherichia coli, yeast cytoplasm, and mammalian cytoplasm have an unusual conserved alpha 2 beta 2 quaternary structure that is shared by only one other aminoacyl-tRNA synthetase. Both subunits are required for activity. We show here that a single mitochondrial polypeptide from Saccharomyces cerevisiae is an active phenylalanyl-tRNA synthetase. This protein (the MSF1 gene product) is active as a monomer. It has all three characteristic sequence motifs of the class II aminoacyl-tRNA synthetases, and its activity may result from the recruitment of additional sequences into an alpha-subunit-like structure.
28