Transfer RNA genes of Euglena gracilis chloroplast DNA - A review

Transfer RNA genes have been mapped to at least nine different loci on the physical map of the Euglena gracilis chloroplast genome. One of these loci in the ribosomal RNA operons is present three times per genome. The DNA sequences of six of the nine different loci, containing 21 different tRNA genes, have been determined. Genes corresponding to the amino acids Ala, Arg, Asn, Cys, Gln, Gly (2), Glu, His, Ile, Leu (2), Met (2), Phe, Ser, Thr, Trp, Tyr, Val, and one unassigned species have been identified. All genes except one are found in clusters of 2-6 genes. None of the known genes contains introns, nor codes for the 3′-CCA terminus. In addition to these genes, two pseudo tRNA genes are present in the rDNA leader region.