Abstract
In yeast, two aminoacyl-tRNA synthetases, MetRS and GluRS, are associated with Arc1p. We have studied the mechanism of this complex formation and found that the non-catalytic N-terminally appended domains of MetRS and GluRS are necessary and sufficient for binding to Arc1p. Similarly, it is the N-terminal domain of Arc1p that contains distinct but overlapping binding sites for MetRS and GluRS. Localization of Arc1p, MetRS and GluRS in living cells using green fluorescent protein showed that these three proteins are cytoplasmic and largely excluded from the nucleus. However, when their assembly into a complex is inhibited, significant amounts of MetRS, GluRS and Arc1p can enter the nucleus. We suggest that the organization of aminoacyl-tRNA synthetases into a multimeric complex not only affects catalysis, but is also a means of segregating the tRNA- aminoacylation machinery mainly to the cytoplasmic compartment.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Amino Acyl-tRNA Synthetases / biosynthesis*
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Amino Acyl-tRNA Synthetases / chemistry*
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Binding Sites
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Catalytic Domain
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Cell Nucleus / metabolism
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Chromosome Deletion
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Glutamate-tRNA Ligase / chemistry
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Glutamate-tRNA Ligase / genetics
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Glutamate-tRNA Ligase / metabolism
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Green Fluorescent Proteins
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Luminescent Proteins / metabolism
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Methionine-tRNA Ligase / chemistry
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Methionine-tRNA Ligase / genetics
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Methionine-tRNA Ligase / metabolism
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Microscopy, Confocal
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Microscopy, Fluorescence
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Models, Biological
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Molecular Sequence Data
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Mutagenesis
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Mutation
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Plasmids / metabolism
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Protein Binding
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Protein Structure, Tertiary
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RNA-Binding Proteins / chemistry*
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RNA-Binding Proteins / metabolism*
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Saccharomyces cerevisiae / enzymology
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Saccharomyces cerevisiae Proteins*
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Sequence Homology, Amino Acid
Substances
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ARC1 protein, S cerevisiae
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Luminescent Proteins
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RNA-Binding Proteins
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Saccharomyces cerevisiae Proteins
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Green Fluorescent Proteins
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Amino Acyl-tRNA Synthetases
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Methionine-tRNA Ligase
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Glutamate-tRNA Ligase