Isolation and characterization of eft-1, an elongation factor 2-like gene on chromosome III of Caenorhabditis elegans.
A gene (eft-1) encoding an elongation factor 2-like protein was isolated from a region adjacent to the polyubiquitin gene, ubq-1, of Caenorhabditis elegans. Sequence analysis of genomic and cDNA clones revealed that the deduced amino acid sequence of the protein (EFT-1) is 38% identical to that of mammalian and Drosophila elongation factor 2 (EF-2). The entire eft-1 gene is approximately 3.8 kb in length and contains 5 exons separated by short introns of 46-75 bp. The 2,547-bp open reading frame predicts a protein of 849 amino acid residues (calculated Mr, 96,151). Conserved sequences shared among a variety of GTP-binding proteins including EF-2 are found in the amino-terminal third of EFT-1. The carboxy-terminal half contains regions with 40-57% similarity (including conservative changes) with segments characteristic of EF-2 and its prokaryotic homolog, EF-G. However, the histidyl residue target for ADP-ribosylation of EF-2 by diphtheria toxin is replaced by tyrosine in EFT-1. Southern and Northern blot analyses indicate that eft-1 is a single-copy gene that is expressed at all stages of nematode development. Amplification of fragments encoding highly conserved regions of EF-2 using the polymerase chain reaction led to the isolation of a fragment encoding the modifiable histidyl residue and which likely represents part of the C. elegans EF-2 gene (eft-2). This suggests that EFT-1 is not the C. elegans homolog of EF-2, but a closely related protein.
Ofulue
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Department of Biochemistry, Faculty of Medicine, University of British Columbia, Vancouver, Canada.
Candido
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D002107:Caenorhabditis / Q000737:chemistry / Q000235:genetics*; D002875:Chromosomes; D003001:Cloning, Molecular; D006224:Cricetinae; D004247:DNA / Q000302:isolation & purification; D005796:Genes; D008969:Molecular Sequence Data; D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D012689:Sequence Homology, Nucleic Acid
D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors; D004247:DNA