Abstract
tRNA maturation involves several steps, including processing, splicing, CCA addition, and posttranscriptional modifications. tRNAHis guanylyltransferase (Thg1) is the only enzyme known to catalyze templated nucleotide addition in the 3′–5′ direction, unlike other DNA and RNA polymerases. For a better understanding of its unique catalytic mechanism at the molecular level, we determined the crystal structure of GTP-bound Thg1 from Saccharomyces cerevisiae at the maximum resolution of 3.0 Å. The structure revealed the enzyme to have a tetrameric conformation that is well conserved among different species, and the GTP molecule was clearly bound at the active site, coordinating with two magnesium ions. In addition, two flexible protomers at the potential binding site (PBS) for tRNAHis were observed. We suggest that the PBS of the tetramer could also be one of the sites for interaction with partner proteins.
Original language | English |
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Pages (from-to) | 400-405 |
Number of pages | 6 |
Journal | Biochemical and biophysical research communications |
Volume | 490 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2017 Aug 19 |
Bibliographical note
Funding Information:We thank the supporting staff of beamline NW12A of the Photon Factory (Tsukuba, Japan) and beamline 5C-SBII of Pohang Accelerator Light Source (Pohang, Korea) for their help with the data collection. This work was supported by grants from the National Research Foundation of Korea (2017R1A2B2005666). KYH was supported by Korea University grants.
Publisher Copyright:
© 2017 Elsevier Inc.
Keywords
- GTP
- Posttranscriptional modifications
- Reverse polymerization
- Thg1
- X-ray structure
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology
- Cell Biology