title: The mammalian hypusine-containing protein, eukaryotic initiation factor 4D. Structural homology of this protein from several species.
abstract: A single cellular protein of Mr approximately 18,000 and pI near 5.1, recently identified as eukaryotic translation initiation factor eIF-4D, contains the unusual amino acid hypusine [N epsilon-(4-amino--2-hydroxybutyl)lysine] formed post-translationally from lysine with a structural contribution from the polyamine spermidine. When the 3H-labeled hypusine-containing protein isolated from Chinese hamster ovary (CHO) cells that were grown with radioactive polyamine is digested with trypsin and the digest is subjected to two-dimensional separation, a single radioactive peptide is seen. A labeled peptide that occupies this same position is found in a digest of the [3H]hypusine protein from human lymphocytes and the single hypusine-containing tryptic peptide from purified rabbit reticulocyte eIF-4D also moves to this identical position. Stepwise Edman degradation of the tryptic digest of CHO cell hypusine-protein releases the radioactivity as a single peak in accordance with our earlier evidence for a single hypusine residue per molecule of eIF-4D. The similar patterns of radioactive peptides obtained from tryptic digests of radioiodinated eIF-4D from CHO cells, human lymphocytes, and rabbit reticulocytes suggest a highly conserved primary structure for this protein.
mesh_terms: D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D006224:Cricetinae; D003412:Cricetulus; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000032:analysis*; D008239:Lysine / Q000031:analogs & derivatives* / Q000032:analysis; D008970:Molecular Weight; D010053:Ovary; D010446:Peptide Fragments / Q000032:analysis; D010448:Peptide Initiation Factors; D016601:RNA-Binding Proteins; D014357:Trypsin; D000097574:Eukaryotic Translation Initiation Factor 5A
chemical_list: D008239:Lysine; D010446:Peptide Fragments; D010448:Peptide Initiation Factors; D016601:RNA-Binding Proteins; D014357:Trypsin; D000097574:Eukaryotic Translation Initiation Factor 5A; C100028:hypusine