Journal
JOURNAL OF BIOLOGICAL CHEMISTRY
Volume 281, Issue 32, Pages 23075-23082Publisher
AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
DOI: 10.1074/jbc.M601606200
Keywords
-
Categories
Funding
- NIGMS NIH HHS [GM63789, GM63107] Funding Source: Medline
Ask authors/readers for more resources
Leucyl-tRNA synthetase (LeuRS) performs dual essential roles in group I intron RNA splicing as well as protein synthesis within the yeast mitochondria. Deletions of the C terminus differentially impact the two functions of the enzyme in splicing and aminoacylation in vivo. Herein, we determined that a five-amino acid C-terminal deletion of LeuRS, which does not complement a null strain, can form a ternary complex with the bI4 intron and its maturase splicing partner. However, the complex fails to stimulate splicing activity. The x-ray co-crystal structure of LeuRS showed that a C-terminal extension of about 60 amino acids forms a discrete domain, which is unique among the LeuRSs and interacts with the corner of the L-shaped tRNA(Leu). Interestingly, deletion of the entire yeast mitochondrial LeuRS C-terminal domain enhanced its aminoacylation and amino acid editing activities. In striking contrast, deletion of the corresponding C-terminal domain of Escherichia coli LeuRS abolished aminoacylation of tRNALeu and also amino acid editing of mischarged tRNA molecules. These results suggest that the role of the leucine-specific C-terminal domain in tRNA recognition for aminoacylation and amino acid editing has adapted differentially and with surprisingly opposite effects. We propose that the secondary role of yeast mitochondrial LeuRS in RNA splicing has impacted the functional evolution of this critical C-terminal domain.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available