RNA-methyltransferase TrmA is a dual-specific enzyme responsible for C5-methylation of uridine in both tmRNA and tRNA.
RNA Biol
; 10(4): 572-8, 2013 Apr.
Article
em En
| MEDLINE
| ID: mdl-23603891
ABSTRACT
In bacteria, trans-translation rescues stalled ribosomes by the combined action of tmRNA (transfer-mRNA) and its associated protein SmpB. The tmRNA 5' and 3' ends fold into a tRNA-like domain (TLD), which shares structural and functional similarities with tRNAs. As in tRNAs, the UUC sequence of the T-arm of the TLD is post-transcriptionally modified to m (5)UψC. In tRNAs of gram-negative bacteria, formation of m (5)U is catalyzed by the SAM-dependent methyltransferase TrmA, while formation of m (5)U at two different positions in rRNA is catalyzed by distinct site-specific methyltransferases RlmC and RlmD. Here, we show that m (5)U formation in tmRNAs is exclusively due to TrmA and should be considered as a dual-specific enzyme. The evidence comes from the lack of m (5)U in purified tmRNA or TLD variants recovered from an Escherichia coli mutant strain deleted of the trmA gene. Detection of m (5)U in RNA was performed by NMR analysis.
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Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
TRNA Metiltransferases
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Uridina
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RNA Bacteriano
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RNA de Transferência
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Proteínas de Escherichia coli
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Escherichia coli
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article