| Abstract: | Sequence comparisons of 5 S and other ribosomal RNAs by segments can be useful in understanding anomalous primary and secondary structures and in assessing phylogenetic relationships. In a segmented analysis, the 5'-half of the Chlamydomonas reinhardii chloroplast 5 S ribosomal RNA is found to have a very close sequence homology to the green plant chloroplast and cyanobacterial 5 S RNAs; however, the 3'-half has a highly unusual sequence. Further comparisons of homologies between regions of the 5 S RNAs from C. reinhardii and the green plant chloroplasts suggest that genetic rearrangements within the 5 S DNA may have produced the unusual sequence at the 3'-half. Segmented analyses of the C. reinhardii and green plant chloroplast 5 S RNAs suggest a close relationship which is not revealed by overall sequence comparisons. |
