RNase D is a 3'-exonuclease whose in vitro specificity has suggested a role in tRNA processing. However, since mutant Escherichia coli strains devoid of RNase D display a normal phenotype, it has not been possible to ascertain the enzyme's fucntion or even to determine which RNA is its substrate in vivo. Here we show that transformation of strains devoid of tRNA nucleotidyl-transferase with a multicopy plasmid carrying the rnd+ gene leads to extremely slow growth due to elevated levels of RNase D activity. Analysis of such a slow-growing strain revealed that less tRNA is present in the cell and that the tRNA that could be recovered is substantially damaged. These studies demonstrate that RNase D can act at the 3' terminus of tRNA in vivo, and they support the conclusion that RNase D participates in tRNA metabolism.
|Original language||English (US)|
|Number of pages||4|
|Journal||Journal of Biological Chemistry|
|State||Published - 1988|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology