5o8w
From Proteopedia
CRYSTAL STRUCTURE ANALYSIS OF THE YEAST ELONGATION FACTOR COMPLEX EEF1A:EEF1BA
Structural highlights
Function[EF1B_YEAST] Catalytic subunit of the guanine nucleotide exchange factor (GEF) (eEF1B subcomplex) of the eukaryotic elongation factor 1 complex (eEF1). Stimulates the exchange of GDP for GTP on elongation factor 1A (eEF1A), probably by displacing GDP from the nucleotide binding pocket in eEF1A. The 30-fold higher concentration of GTP compared to GDP in cells favors the formation of eEF1A-GTP, which rapidly forms a ternary complex with aminoacyl-tRNA that in turn displaces eEF1B from the complex.[1] Publication Abstract from PubMedRibosomal translation factors are fundamental for protein synthesis and highly conserved in all kingdoms of life. The essential eukaryotic elongation factor 1A (eEF1A), delivers aminoacyl tRNAs to the A-site of the translating 80S ribosome. Several studies have revealed that eEF1A is posttranslationally modified. Using MS analysis, site-directed mutagenesis, and X-ray structural data analysis of Saccharomyces cerevisiae eEF1A, we identified a posttranslational modification in which the alpha amino group of mono-L-glutamine is covalently linked to the side chain of glutamate 45 in eEF1A. The MS analysis suggested that all eEF1A molecules are modified by this glutaminylation and that this posttranslational modification occurs at all stages of yeast growth. The mutational studies revealed that this glutaminylation is not essential for the normal functions of eEF1A in S. cerevisiae However, eEF1A glutaminylation slightly reduced growth under antibiotic-induced translational stress conditions. Moreover, we identified the same posttranslational modification in eEF1A from Schizosaccharomyces pombe, but not in various other eukaryotic organisms tested despite strict conservation of the Glu-45 residue among these organisms. We therefore conclude that eEF1A glutaminylation is a yeast-specific posttranslational modification, which appears to influence protein translation. Protein glutaminylation is a yeast-specific posttranslational modification of elongation factor 1A.,Jank T, Belyi Y, Wirth C, Rospert S, Hu Z, Dengjel J, Tzivelekidis T, Andersen GR, Hunte C, Schlosser A, Aktories K J Biol Chem. 2017 Aug 11. pii: jbc.M117.801035. doi: 10.1074/jbc.M117.801035. PMID:28801462[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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