Crystal structure of tRNAHis guanylyltransferase from Saccharomyces cerevisiae.
Biochem Biophys Res Commun
; 490(2): 400-405, 2017 08 19.
Article
em En
| MEDLINE
| ID: mdl-28623126
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.
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MEDLINE
Assunto principal:
Saccharomyces cerevisiae
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Proteínas de Saccharomyces cerevisiae
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Nucleotidiltransferases
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article