A unique tRNA recognition mechanism of Caenorhabditis elegans mitochondrial EF-Tu2

Takuma Suematsu, Aya Sato, Masayuki Sakurai, Kimitsuna Watanabe, Takashi Ohtsuki

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Nematode mitochondria expresses two types of extremely truncated tRNAs that are specifically recognized by two distinct elongation factor Tu (EF-Tu) species named EF-Tu1 and EF-Tu2. This is unlike the canonical EF-Tu molecule that participates in the standard protein biosynthesis systems, which basically recognizes all elongator tRNAs. EF-Tu2 specifically recognizes Ser-tRNASer that lacks a D arm but has a short T arm. Our previous study led us to speculate the lack of the D arm may be essential for the tRNA recognition of EF-Tu2. However, here, we showed that the EF-Tu2 can bind to D arm-bearing Ser-tRNAs, in which the D-T arm interaction was weakened by the mutations. The ethylnitrosourea-modification interference assay showed that EF-Tu2 is unique, in that it interacts with the phosphate groups on the T stem on the side that is opposite to where canonical EF-Tu binds. The hydrolysis protection assay using several EF-Tu2 mutants then strongly suggests that seven C-terminal amino acid residues of EF-Tu2 are essential for its aminoacyl-tRNA-binding activity. Our results indicate that the formation of the nematode mitochondrial (mt) EF-Tu2/GTP/aminoacyl-tRNA ternary complex is probably supported by a unique interaction between the C-terminal extension of EF-Tu2 and the tRNA.

Original languageEnglish
Pages (from-to)4683-4691
Number of pages9
JournalNucleic acids research
Volume33
Issue number15
DOIs
Publication statusPublished - Oct 17 2005

ASJC Scopus subject areas

  • Genetics

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