The eukaryotic translation initiation factor 5, eIF-5, a protein from Zea mays, containing a zinc-finger structure, binds nucleic acids in a zinc-dependent manner.
A maize cDNA encoding the eukaryotic translation initiation factor 5 (eIF-5) has been isolated from an 8-day-old seedling cDNA library. The 1975 bp cDNA encodes a protein of 451 amino acids, with a predicted molecular weight of 49.04 kDa, and hybridizes to a single sequence in the maize genome. The deduced sequence contains motifs characteristic of proteins belonging to the GPTase superfamily, a zinc finger well conserved in all the protein sequences for eIF-5 reported so far, and a fragment also present in prokaryotic and chloroplast L11 ribosomal protein. Polymer-binding assays have been used to assess the predicted RNA binding property of the protein and to characterize its function. It is shown that the eIF-5-encoded protein binds to single-stranded DNA and to polyuridylic acid and that the binding is dependent on the presence of Zn2+ ions. These results suggest that the zinc-finger structure is involved in the binding of the eIF-5 protein to RNA.
López Ribera
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Departament de Genètica Molecular, CID-CSIC, Jordi Girona, Barcelona, Spain.
Ruiz-Avila
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Puigdomènech
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P
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D040061:Eukaryotic Initiation Factor-5; D008969:Molecular Sequence Data; D010448:Peptide Initiation Factors / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism; D011485:Protein Binding; D012313:RNA / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D003313:Zea mays; D015032:Zinc / Q000378:metabolism; D016335:Zinc Fingers
D040061:Eukaryotic Initiation Factor-5; D010448:Peptide Initiation Factors; D010940:Plant Proteins; D016601:RNA-Binding Proteins; D012313:RNA; D015032:Zinc