Investigation of the conserved glutamate immediately following the DEAD box in eukaryotic translation initiation factor 4AI.
The DExD-box family (DEAD-box) of proteins was surveyed for eukaryotic translation initiation factor 4A-specific sequences surrounding the DEAD box. An eIF4A-unique glutamate residue (E186 in eIF4AI) was identified immediately following the D-E-A-D sequence in eIF4AI, II, and III that was found to be conserved from yeast to Man. Mutation to a selection of alternative amino acids was performed within recombinant eIF4AI expressed in Escherichia coli and mutant proteins were surveyed for RNA-dependent ATPase activity. The mutants were also investigated for changes in activity in the presence of the two eIF4AI-binding domains of eIF4GI as well as for co-purification ability to these two domains. The E186 residue was found to be of significance for RNA-dependent ATPase activity for eIF4AI alone and in the presence of eIF4AI-binding domains of eIF4GI through point-mutation analysis. Furthermore, binding interactions between eIF4AI and eIF4GI domains were also significantly influenced by mutation of E186, as observed through co-purification assays. Thus, this residue appears to be of functional significance for eIF4A.
Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY 11439, USA.
Krishnaben
K
Patel
Grishma K
GK
Shah
Sai Shilpa
SS
Kommaraju
Woon-Kai
WK
Low
D000251:Adenosine Triphosphatases / Q000737:chemistry*; D039601:Eukaryotic Initiation Factor-4A / Q000737:chemistry* / Q000235:genetics; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics; D018698:Glutamic Acid / Q000737:chemistry*; D006801:Humans; D009154:Mutation; D011485:Protein Binding
D005656:Fungal Proteins; D018698:Glutamic Acid; D039601:Eukaryotic Initiation Factor-4A; D000251:Adenosine Triphosphatases; C027900:RNA-dependent ATPase