Aminoacylation of Phaseolus vulgaris cytoplasmic, chloroplastic and mitochondrial tRNAsPro and tRNAsLys by homologous and heterologous enzymes

Abstract

The cytoplasmic prolyl-tRNA synthetase can be separated by hydroxyapatite chromatography, from the enzyme present in the chloroplasts and in the mitochondria (organellar enzyme). The cytoplasmic lysyl-tRNA synthetase can also be separated from the organellar enzyme. There are two tRNAsPro in the cytoplasm; they can be charged by the cytoplasmic enzyme, but not by the organellar enzyme or the Escherichia coli enzyme. Chloroplasts contain, in addition to the two cytoplasmic tRNAsPro, one chloroplast-specific tRNAPro, which is not recognized by the cytoplasmic enzyme, but can be charged by the organellar or the E. coli enzyme. Mitochondria contain, in addition to the two cytoplasmic tRNAsPro, two mitochondria-specific tRNAsPro, which are not recognized by the cytoplasmic enzyme, but can be charged by the organellar or the E. coli enzyme. There are two tRNAsLys in the cytoplasm. Both can be charged by the cytoplasmic enzyme, but one can be charged by the organellar or E. coli enzyme. Chloroplasts contain in addition to one cytoplasmic tRNALys, one chloroplast-specific tRNALys which can only be charged by the organellar or E. coli enzyme. Mitochondria contain, in addition to one cytoplasmic tRNALys, one mitochondria-specific tRNALys which can only be charged by the organellar or E. coli enzyme.