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From Proteopedia
Crystal structure of archaeal Pelota and GTP-bound EF1 alpha complex
Structural highlights
Function[EF1A_AERPE] This protein promotes the GTP-dependent binding of aminoacyl-tRNA to the A-site of ribosomes during protein biosynthesis (By similarity). [PELO_AERPE] May function in recognizing stalled ribosomes, interact with stem-loop structures in stalled mRNA molecules, and effect endonucleolytic cleavage of the mRNA. May play a role in the release non-functional ribosomes and degradation of damaged mRNAs. Has endoribonuclease activity (By similarity). Publication Abstract from PubMedNo-go decay and nonstop decay are mRNA surveillance pathways that detect translational stalling and degrade the underlying mRNA, allowing the correct translation of the genetic code. In eukaryotes, the protein complex of Pelota (yeast Dom34) and Hbs1 translational GTPase recognizes the stalled ribosome containing the defective mRNA. Recently, we found that archaeal Pelota (aPelota) associates with archaeal elongation factor 1alpha (aEF1alpha) to act in the mRNA surveillance pathway, which accounts for the lack of an Hbs1 ortholog in archaea. Here we present the complex structure of aPelota and GTP-bound aEF1alpha determined at 2.3-A resolution. The structure reveals how GTP-bound aEF1alpha recognizes aPelota and how aPelota in turn stabilizes the GTP form of aEF1alpha. Combined with the functional analysis in yeast, the present results provide structural insights into the molecular interaction between eukaryotic Pelota and Hbs1. Strikingly, the aPelota.aEF1alpha complex structurally resembles the tRNA.EF-Tu complex bound to the ribosome. Our findings suggest that the molecular mimicry of tRNA in the distorted "A/T state" conformation by Pelota enables the complex to efficiently detect and enter the empty A site of the stalled ribosome. Structural basis for mRNA surveillance by archaeal Pelota and GTP-bound EF1alpha complex.,Kobayashi K, Kikuno I, Kuroha K, Saito K, Ito K, Ishitani R, Inada T, Nureki O Proc Natl Acad Sci U S A. 2010 Oct 12;107(41):17575-9. Epub 2010 Sep 27. PMID:20876129[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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