Characterization of two homologous 2'-O-methyltransferases showing different specificities for their tRNA substrates.

TitleCharacterization of two homologous 2'-O-methyltransferases showing different specificities for their tRNA substrates.
Publication TypeJournal Article
Year of Publication2014
AuthorsSomme, J., Van Laer B., Roovers M., Steyaert J., Versées W., and Droogmans L.
JournalRNA
Volume20
Issue8
Pagination1257-71
Date Published2014 Aug
ISSN1469-9001
KeywordsArchaea, Bacterial Proteins, Catalysis, Escherichia coli, Inverted Repeat Sequences, Models, Molecular, Mutation, Nucleic Acid Conformation, Nucleosides, Protein Binding, Protein Conformation, Protein Interaction Domains and Motifs, Protein Multimerization, Reproducibility of Results, RNA, Transfer, Substrate Specificity, tRNA Methyltransferases
Abstract

The 2'-O-methylation of the nucleoside at position 32 of tRNA is found in organisms belonging to the three domains of life. Unrelated enzymes catalyzing this modification in Bacteria (TrmJ) and Eukarya (Trm7) have already been identified, but until now, no information is available for the archaeal enzyme. In this work we have identified the methyltransferase of the archaeon Sulfolobus acidocaldarius responsible for the 2'-O-methylation at position 32. This enzyme is a homolog of the bacterial TrmJ. Remarkably, both enzymes have different specificities for the nature of the nucleoside at position 32. While the four canonical nucleosides are substrates of the Escherichia coli enzyme, the archaeal TrmJ can only methylate the ribose of a cytidine. Moreover, the two enzymes recognize their tRNA substrates in a different way. We have solved the crystal structure of the catalytic domain of both enzymes to gain better understanding of these differences at a molecular level.

DOI10.1261/rna.044503.114
Alternate JournalRNA
PubMed ID24951554
PubMed Central IDPMC4105751
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