title: GTP interacts through its ribose and phosphate moieties with different subunits of the eukaryotic initiation factor eIF-2.
abstract: We have previously shown that a GTP derivative bearing p-azidoaniline at the gamma-phosphate group specifically labels the gamma-subunit of eukaryotic initiation factor eIF-2. In the present study a new GTP derivative carrying the photoreactive group at the ribose moiety of GTP was applied for affinity labeling of eIF-2 in different initiation complexes. Using this GTP analogue the beta-subunit of eIF-2 was found to be specifically labeled in all complexes investigated. It is concluded that GTP interacts with both the beta- and gamma-subunit of eIF-2: the guanosine moiety is in contact with the beta-subunit and the gamma-phosphate group with the gamma-subunit.
authors.affiliation: Academy of Sciences of the GDR, Department of Cell Physiology, Berlin-Buch.
authors.forename: U A
authors.initials: UA
authors.lastname: Bommer
authors.forename: T V
authors.initials: TV
authors.lastname: Kurzchalia
mesh_terms: D000345:Affinity Labels / Q000378:metabolism; D000818:Animals; D001389:Azirines / Q000138:chemical synthesis / Q000378:metabolism*; D001665:Binding Sites; D015852:Eukaryotic Initiation Factor-2; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000378:metabolism*; D008099:Liver / Q000378:metabolism; D046911:Macromolecular Substances; D008970:Molecular Weight; D010448:Peptide Initiation Factors / Q000378:metabolism*; D010761:Phosphorus Radioisotopes; D011506:Proteins / Q000378:metabolism*; D051381:Rats
chemical_list: C058756:4-(3-trifluoromethyldiazino)benzoylhydrazone-oxidized GTP; D000345:Affinity Labels; D001389:Azirines; D015852:Eukaryotic Initiation Factor-2; D046911:Macromolecular Substances; D010448:Peptide Initiation Factors; D010761:Phosphorus Radioisotopes; D011506:Proteins; D006160:Guanosine Triphosphate