Specificity shifts in the rRNA and tRNA nucleotide targets of archaeal and bacterial m5U methyltransferases.
RNA
; 17(1): 45-53, 2011 Jan.
Article
em En
| MEDLINE
| ID: mdl-21051506
Methyltransferase enzymes that use S-adenosylmethionine as a cofactor to catalyze 5-methyl uridine (m(5)U) formation in tRNAs and rRNAs are widespread in Bacteria and Eukaryota, but are restricted to the Thermococcales and Nanoarchaeota groups amongst the Archaea. The RNA m(5)U methyltransferases appear to have arisen in Bacteria and were then dispersed by horizontal transfer of an rlmD-type gene to the Archaea and Eukaryota. The bacterium Escherichia coli has three gene paralogs and these encode the methyltransferases TrmA that targets m(5)U54 in tRNAs, RlmC (formerly RumB) that modifies m(5)U747 in 23S rRNA, and RlmD (formerly RumA) the archetypical enzyme that is specific for m(5)U1939 in 23S rRNA. The thermococcale archaeon Pyrococcus abyssi possesses two m(5)U methyltransferase paralogs, PAB0719 and PAB0760, with sequences most closely related to the bacterial RlmD. Surprisingly, however, neither of the two P. abyssi enzymes displays RlmD-like activity in vitro. PAB0719 acts in a TrmA-like manner to catalyze m(5)U54 methylation in P. abyssi tRNAs, and here we show that PAB0760 possesses RlmC-like activity and specifically methylates the nucleotide equivalent to U747 in P. abyssi 23S rRNA. The findings indicate that PAB0719 and PAB0760 originated as RlmD-type m(5)U methyltransferases and underwent changes in target specificity after their acquisition by a Thermococcales ancestor from a bacterial source.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
RNA Ribossômico
/
RNA de Transferência
/
Archaea
/
Pyrococcus abyssi
/
Metiltransferases
Idioma:
En
Revista:
RNA
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
França
País de publicação:
Estados Unidos