Import of several tRNAs from the cytoplasm into the mitochrondria in bean Phaseolus vulgaris

Abstract

Four P. Vulgaris mitochondrial tRNALeu species have been shown to be nuclear encoded. These mt tRNAsLeu can be used for in vitro protein synthesis. We found that the sequences of P. vulgaris mitochondrial and cytoplasmic tRNAsLeu(NAG) are Identical except for a post-transcriptional modification occuring at position 18 (Gm in mt tRNALeu instead of G in cyt tRNALeu), as in the case of mt and cyt tRNAsLeu(NAA) already sequenced (1). This post-transcriptional modification has also been found in two other bean mt tRNALeu species, but not in P. vulgaris cytoplasmic tRNALeu species that we have purified so far.Furthermore, comparison of the 2-D polyacrylamide gel electrophoretic patterns of tRNAs eluted from bean mt tRNA-mtDNA and mt tRNA-nDNA hybrids revealed at least 8 mt tRNAs coded for by the nuclear genome. © 1988 IRL Press Limited.