Crystallographic capture of a radical S-adenosylmethionine enzyme in the act of modifying tRNA.
Science
; 352(6283): 309-12, 2016 Apr 15.
Article
em En
| MEDLINE
| ID: mdl-27081063
ABSTRACT
RlmN is a dual-specificity RNA methylase that modifies C2 of adenosine 2503 (A2503) in 23S rRNA and C2 of adenosine 37 (A37) in several Escherichia coli transfer RNAs (tRNAs). A related methylase, Cfr, modifies C8 of A2503 via a similar mechanism, conferring resistance to multiple classes of antibiotics. Here, we report the x-ray structure of a key intermediate in the RlmN reaction, in which a Cys(118)âAla variant of the protein is cross-linked to a tRNA(Glu)substrate through the terminal methylene carbon of a formerly methylcysteinyl residue and C2 of A37. RlmN contacts the entire length of tRNA(Glu), accessing A37 by using an induced-fit strategy that completely unfolds the tRNA anticodon stem-loop, which is likely critical for recognition of both tRNA and ribosomal RNA substrates.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
RNA Bacteriano
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RNA de Transferência de Ácido Glutâmico
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Proteínas de Escherichia coli
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Metiltransferases
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article