Localization and structural analysis of the ribosomal RNA operons ofRhodobacter sphaeroides

作者：Sylvia C. Dryden, Samuel Kaplan · 发表于：Nucleic Acids Research · 年份：1990 · DOI：10.1093/nar/18.24.7267 · 被引用次数：151 · 研究领域：Genomics and Phylogenetic Studies、Photosynthetic Processes and Mechanisms、Protist diversity and phylogeny

We have identified, cloned and sequenced the three ribosomal RNA (rRNA) operons (rrn) present in the facultative photoheterotroph Rhodobacter sphaeroides. DNA sequence analysis has identified the 16S, 23S, and 5S rRNAs, two tRNAs (ile and ala) in the spacer region between the 16S and 23S rRNAs, and an f-met tRNA immediately following the 5S rRNA gene of all three operons. Physical mapping, genetic analysis, and Southern hybridization data indicate that rrnA is contained on a large chromosome and rrnB and rrnC are contained on a second smaller chromosome. These findings are discussed in relation to the origins of diploidy.