Trans-kingdom rescue of Gln-tRNAGln synthesis in yeast cytoplasm and mitochondria.
Nucleic Acids Res
; 40(18): 9171-81, 2012 Oct.
Article
em En
| MEDLINE
| ID: mdl-22821561
ABSTRACT
Aminoacylation of transfer RNA(Gln) (tRNA(Gln)) is performed by distinct mechanisms in different kingdoms and represents the most diverged route of aminoacyl-tRNA synthesis found in nature. In Saccharomyces cerevisiae, cytosolic Gln-tRNA(Gln) is generated by direct glutaminylation of tRNA(Gln) by glutaminyl-tRNA synthetase (GlnRS), whereas mitochondrial Gln-tRNA(Gln) is formed by an indirect pathway involving charging by a non-discriminating glutamyl-tRNA synthetase and the subsequent transamidation by a specific Glu-tRNA(Gln) amidotransferase. Previous studies showed that fusion of a yeast non-specific tRNA-binding cofactor, Arc1p, to Escherichia coli GlnRS enables the bacterial enzyme to substitute for its yeast homologue in vivo. We report herein that the same fusion enzyme, upon being imported into mitochondria, substituted the indirect pathway for Gln-tRNA(Gln) synthesis as well, despite significant differences in the identity determinants of E. coli and yeast cytosolic and mitochondrial tRNA(Gln) isoacceptors. Fusion of Arc1p to the bacterial enzyme significantly enhanced its aminoacylation activity towards yeast tRNA(Gln) isoacceptors in vitro. Our study provides a mechanism by which trans-kingdom rescue of distinct pathways of Gln-tRNA(Gln) synthesis can be conferred by a single enzyme.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
RNA de Transferência de Glutamina
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Citoplasma
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Aminoacilação de RNA de Transferência
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Aminoacil-tRNA Sintetases
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Mitocôndrias
Idioma:
En
Revista:
Nucleic Acids Res
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
China