Nucleic Acids Research, 1984, Vol. 12, No. 21 8253-8268
© 1984
MOLECULAR BIOLOGY |
A transfer RNAArg gene of Pelargonium chloroplasts, but not a 5S RNA gene, is efficiently transcribed after injection into Xenopus oocyte nuclei
Zentralinstitut für Genetik und Kulturpflanzenforschung der Akademie der Wissenschaften der GDR GDR-4325 Gatersleben 1Wissenschaftsbereich Genetik der Sektion Biowissenschaften der Martin-Luther-Universität Halle GDR-4020 Halle/Saale, GDR
Received August 10, 1984. Revised October 2, 1984. Accepted October 15, 1984.
We present the primary structure of a chloroplast
gene of the plant, Pelargonium zonale, and its faithful expression in Xenopus oocyte nuclei. This tRNAArg gene is located 250 bp downstream of a 5S RNA gene within a cloned 5kb long ribosomal DNA segment (Fig.l). The Pelargonium tRNAArg gene shares 97% and 86% sequence homology with
genes of Spirodela oligorhiza and Euglena gracilis chloroplasts, respectively, and also extensive homology (70%) with the corresponding gene of E.coli. It lacks an intervening sequence and, like eukaryotic tRNA genes, does not code for the 3' terminal CCA nucleotides. Moreover, the chloroplast tRNAArg gene carries all the sequence elements essential for transcription by vertebrate RNA polymerase III since it is efficiently expressed in Xenopus oocyte nuclei, even in the presence of lµg/ml
-amanitin. In Xenopus oocyte nuclei, no transcripts of the chloroplast 5S RNA gene were detected.
*Present address: Institut für Molekularbiologie II der Universitat Zürich, CH-8093 Zürich, Switzerland