title: Crystal structures of nucleotide exchange intermediates in the eEF1A-eEF1Balpha complex.
abstract: In the elongation cycle of protein biosynthesis, the nucleotide exchange factor eEF1Balpha catalyzes the exchange of GDP bound to the G-protein, eEF1A, for GTP. To obtain more information about the recently solved eEF1A-eEF1Balpha structure, we determined the structures of the eEF1A-eEF1Balpha-GDP-Mg2+, eEF1A-eEF1Balpha-GDP and eEF1A-eEF1Balpha-GDPNP complexes at 3.0, 2.4 and 2.05 A resolution, respectively. Minor changes, specifically around the nucleotide binding site, in eEF1A and eEF1Balpha are consistent with in vivo data. The base, sugar and alpha-phosphate bind as in other known nucleotide G-protein complexes, whereas the beta- and gamma-phosphates are disordered. A mutation of Lys 205 in eEF1Balpha that inserts into the Mg2+ binding site of eEF1A is lethal. This together with the structures emphasizes the essential role of Mg2+ in nucleotide exchange in the eEF1A-eEF1Balpha complex.
authors.affiliation: Institute of Molecular and Structural Biology, University of Aarhus, Gustav Wieds Vej 10C, DK-8000, Aarhus C, Denmark. grand@imsb.au.dk
authors.forename: G R
authors.initials: GR
authors.lastname: Andersen
authors.forename: L
authors.initials: L
authors.lastname: Valente
authors.forename: L
authors.initials: L
authors.lastname: Pedersen
authors.forename: T G
authors.initials: TG
authors.lastname: Kinzy
authors.forename: J
authors.initials: J
authors.lastname: Nyborg
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics; D001665:Binding Sites; D050260:Carbohydrate Metabolism; D018360:Crystallography, X-Ray; D006153:Guanosine Diphosphate / Q000031:analogs & derivatives / Q000378:metabolism*; D008239:Lysine / Q000235:genetics / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism; D008958:Models, Molecular; D009154:Mutation / Q000235:genetics; D009963:Orotic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D020648:Peptide Elongation Factor 1 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011487:Protein Conformation; D015003:Yeasts / Q000737:chemistry* / Q000187:drug effects / Q000235:genetics / Q000378:metabolism
chemical_list: D020648:Peptide Elongation Factor 1; D006153:Guanosine Diphosphate; D009963:Orotic Acid; C001242:5-fluoroorotic acid; D008274:Magnesium; D008239:Lysine