Translation elongation factor 3: a fungus-specific translation factor?
Fungi appear to be unique in their requirement for a third soluble translation elongation factor. This factor, designated elongation factor 3 (EF-3), was first described in the yeast Saccharomyces cerevisiae and has subsequently been identified in a wide range of fungal species including Candida albicans and Schizosaccharomyces pombe. EF-3 exhibits ribosome-dependent ATPase and GTPase activities that are not intrinsic to the fungal ribosome, but which are essential for translation elongation. Recent studies on the structure of EF-3 from several fungal species have shown that it consists of a repeated domain, with each domain containing the expected putative ATP- and GTP-binding motifs. Overall, EF-3 shows striking amino acid similarity to members of the ATP-binding Cassette (ABC) family of membrane-associated transport proteins although EF-3 is not itself directly membrane-associated. Regions of the EF-3 polypeptide also show structural homology with other translation-associated factors including aminoacyl-tRNA synthetases and the Escherichia coli ribosomal protein S5. While the precise role of EF-3 in the translation elongation cycle remains to be defined, recent evidence suggests that it may be involved in optimizing accuracy during mRNA decoding at the ribosomal A site. Furthermore, the essential nature of EF-3 with respect to the fungal cell indicates that it may be an effective antifungal target. Its apparently ubiquitous occurrence throughout the fungal kingdom also suggests that it may be a useful fungal taxonomic marker.
Belfield
G P
GP
Biological Laboratory, University of Kent, Canterbury, UK.
Tuite
M F
MF
D000595:Amino Acid Sequence; D005656:Fungal Proteins; D005658:Fungi / Q000235:genetics*; D008969:Molecular Sequence Data; D010441:Peptide Chain Elongation, Translational; D010445:Peptide Elongation Factors / Q000235:genetics / Q000378:metabolism; D014176:Protein Biosynthesis; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
D005656:Fungal Proteins; D010445:Peptide Elongation Factors; D029701:Saccharomyces cerevisiae Proteins; C111584:YEF3 protein, S cerevisiae