The Nucleotide sequences of the regions flanking the genes coding for 23S, 16S and 4.5S ribosomal RNA on cfaloroplast DNA from Spirodela oligorhiza

The nucleotide sequences of the flanking regions of the genes coding for Spirodela oligorhiza chloroplast ribosonal RNA's have been determined. We have compared these sequences to the corresponding ones in chloroplast DNA of other plants and of E. coli and finda striking sequential or structural homology. The region 5′-proxinal to the gene coding for 16S rRNA contains a gene coding fort RNAval, which is transcribed from the same strand. In this area' three prokaryotic promoter motifsare found: one located in front of the tRNAval gene and twoin the intergenic space between this gene and the 16S rRNA gene. The niddle one is used for the start of the transcription of the large ribosomal RNA precursor.