2B7C

Yeast guanine nucleotide exchange factor eEF1Balpha K205A mutant in complex with eEF1A

Summary for 2B7C

• Entry DOI: 10.2210/pdb2b7c/pdb
• Related: 1B64 1F60 1G7C 1IJE 1IJF 2B7B
• Descriptor: Elongation factor 1-alpha, elongation factor-1 beta (3 entities in total)
• Functional Keywords: g-protein-gef complex, eef1a, eef1balpha, translation
• Biological source: Saccharomyces cerevisiae (baker's yeast); More
• Cellular location: Cytoplasm: P02994
• Total number of polymer chains: 2
• Total formula weight: 60525.35

Authors

Pittman, Y.R.,Valente, L.,Jeppesen, M.G.,Andersen, G.R.,Patel, S.,Kinzy, T.G. (deposition date: 2005-10-04, release date: 2006-05-02, Last modification date: 2023-10-25)

Primary citation

Pittman, Y.R.,Valente, L.,Jeppesen, M.G.,Andersen, G.R.,Patel, S.,Kinzy, T.G.
Mg2+ and a key lysine modulate exchange activity of eukaryotic translation elongation factor 1B alpha
J.Biol.Chem., 281:19457-19468, 2006

PubMed Abstract: To sustain efficient translation, eukaryotic elongation factor B alpha (eEF1B alpha) functions as the guanine nucleotide exchange factor for eEF1A. Stopped-flow kinetics using 2'-(or 3')-O-N-methylanthraniloyl (mant)-GDP showed spontaneous release of nucleotide from eEF1A is extremely slow and accelerated 700-fold by eEF1B alpha. The eEF1B alpha-stimulated reaction was inhibited by Mg2+ with a K(1/2) of 3.8 mM. Previous structural studies predicted the Lys-205 residue of eEF1B alpha plays an important role in promoting nucleotide exchange by disrupting the Mg2+ binding site. Co-crystal structures of the lethal K205A mutant in the catalytic C terminus of eEF1B alpha with eEF1A and eEF1A.GDP established that the lethality was not due to a structural defect. Instead, the K205A mutant drastically reduced the nucleotide exchange activity even at very low concentrations of Mg2+. A K205R eEF1B alpha mutant on the other hand was functional in vivo and showed nearly wild-type nucleotide dissociation rates but almost no sensitivity to Mg2+. These results indicate the significant role of Mg2+ in the nucleotide exchange reaction by eEF1B alpha and establish the catalytic function of Lys-205 in displacing Mg2+ from its binding site.

PubMed: 16675455
DOI: 10.1074/jbc.M601076200

Experimental method

X-RAY DIFFRACTION (1.8 Å)