Abstract
Eukaryotic initiation factor 1A (eIF1A) and the GTPase IF2/eIF5B are the only universally conserved translation initiation factors. Recent structural, biochemical and genetic data indicate that these two factors form an evolutionarily conserved structural and functional unit in translation initiation. Based on insights gathered from studies of the translation elongation factor GTPases, we propose that these factors occupy the aminoacyl-tRNA site (A site) on the ribosome, and promote initiator tRNA binding and ribosomal subunit joining. These processes yield a translationally competent ribosome with Met-tRNA in the ribosomal peptidyl-tRNA site (P site), base-paired to the AUG start codon of a mRNA.
Publication types
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Comparative Study
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Bacterial Proteins / chemistry
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Bacterial Proteins / physiology
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Binding Sites
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Eukaryotic Initiation Factor-1*
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Eukaryotic Initiation Factor-5
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Evolution, Molecular
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Guanosine Triphosphate / metabolism
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Humans
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Models, Molecular
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Peptide Chain Initiation, Translational*
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Peptide Initiation Factors / chemistry
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Peptide Initiation Factors / genetics
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Peptide Initiation Factors / physiology*
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Protein Structure, Tertiary
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RNA, Transfer, Met / metabolism
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Ribosomes / metabolism*
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Sequence Alignment
Substances
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Bacterial Proteins
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Eukaryotic Initiation Factor-1
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Eukaryotic Initiation Factor-5
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Peptide Initiation Factors
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RNA, Transfer, Met
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eukaryotic peptide initiation factor-1A
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Guanosine Triphosphate