You are not currently logged in.
Access your personal account or get JSTOR access through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
A Conserved Heptamer Motif for Ribosomal RNA Transcription Termination in Animal Mitochondria
Jose R. Valverde, Roberto Marco and Rafael Garesse
Proceedings of the National Academy of Sciences of the United States of America
Vol. 91, No. 12 (Jun. 7, 1994), pp. 5368-5371
Published by: National Academy of Sciences
Stable URL: http://www.jstor.org/stable/2364740
Page Count: 4
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
A search of sequence data bases for a tridecamer transcription termination signal, previously described in human mtDNA as being responsible for the accumulation of mitochondrial ribosomal RNAs (rRNAs) in excess over the rest of mitochondrial genes, has revealed that this termination signal occurs in equivalent positions in a wide variety of organisms from protozoa to mammals. Due to the compact organization of the mtDNA, the tridecamer motif usually appears as part of the 3' adjacent gene sequence. Because in phylogenetically widely separated organisms the mitochondrial genome has experienced many rearrangements, it is interesting that its occurrence near the 3' end of the large rRNA is independent of the adjacent gene. The tridecamer sequence has diverged in phylogenetically widely separated organisms. Nevertheless, a well-conserved heptamer-TGGCAGA, the mitochondrial rRNA termination box-can be defined. Although extending the experimental evidence of its role as a transcription termination signal in humans will be of great interest, its evolutionary conservation strongly suggests that mitochondrial rRNA transcription termination could be a widely conserved mechanism in animals. Furthermore, the conservation of a homologous tridecamer motif in one of the last 3' secondary loops of nonmitochondrial 23S-like rRNAs suggests that the role of the sequence has changed during mitochondrial evolution.
Proceedings of the National Academy of Sciences of the United States of America © 1994 National Academy of Sciences