Localization and structural analysis of the ribosomal RNA operons of Rhodobacter sphaeroides.
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.
Dryden
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Department of Microbiology, University of Texas Health Science Center, Houston 77225.
Kaplan
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D001483:Base Sequence; D015139:Blotting, Southern; D003001:Cloning, Molecular; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009876:Operon; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D012338:RNA, Ribosomal, 23S / Q000235:genetics*; D012341:RNA, Ribosomal, 5S / Q000235:genetics*; D015183:Restriction Mapping; D012242:Rhodobacter sphaeroides / Q000235:genetics*
D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012338:RNA, Ribosomal, 23S; D012341:RNA, Ribosomal, 5S