Structural highlights
Function
[EIF2D_HUMAN] Translation initiation factor that is able to deliver tRNA to the P-site of the eukaryotic ribosome in a GTP-independent manner. The binding of Met-tRNA(I) occurs after the AUG codon finds its position in the P-site of 40S ribosomes, the situation that takes place during initiation complex formation on some specific RNAs. Its activity in tRNA binding with 40S subunits does not require the presence of the aminoacyl moiety. Possesses the unique ability to deliver non-Met (elongator) tRNAs into the P-site of the 40S subunit. In addition to its role in initiation, can promote release of deacylated tRNA and mRNA from recycled 40S subunits following ABCE1-mediated dissociation of post-termination ribosomal complexes into subunits.[1] [2]
Publication Abstract from PubMed
Protein synthesis is a key process in all living organisms. In eukaryotes, Initiation Factor 2 (eIF2) plays an important role in translation initiation as it selects and delivers the initiator tRNA to the small ribosomal subunit. Under stress conditions, phosphorylation of the alpha-subunit of eIF2 downregulates cellular protein synthesis. However, translation of certain mRNAs continues via the eIF2D dependent non-canonical initiation pathway. The molecular mechanism of this process remains elusive. In addition, eIF2D plays a role in translation re-initiation and ribosome recycling. Currently, there has been no structural information of eIF2D. We have now determined the crystal structure of the C-terminal domains of eIF2D at 1.4A resolution. One domain has the fold similar to that of eIF1, which is crucial for the scanning and initiation codon selection. The second domain has a known SWIB/MDM2 fold, which was not observed before in other translation initiation factors. Our structure reveals atomic details of inter-domain interactions in the C-terminal part of eIF2D and sheds light on the possible role of these domains in eIF2D during translation.
Crystal Structure of the C-terminal Domain of Human eIF2D and its Implications on Eukaryotic Translation Initiation.,Vaidya AT, Lomakin IB, Joseph NN, Dmitriev SE, Steitz TA J Mol Biol. 2017 Jul 20. pii: S0022-2836(17)30352-2. doi:, 10.1016/j.jmb.2017.07.015. PMID:28736176[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Dmitriev SE, Terenin IM, Andreev DE, Ivanov PA, Dunaevsky JE, Merrick WC, Shatsky IN. GTP-independent tRNA delivery to the ribosomal P-site by a novel eukaryotic translation factor. J Biol Chem. 2010 Aug 27;285(35):26779-87. doi: 10.1074/jbc.M110.119693. Epub, 2010 Jun 21. PMID:20566627 doi:http://dx.doi.org/10.1074/jbc.M110.119693
- ↑ Skabkin MA, Skabkina OV, Dhote V, Komar AA, Hellen CU, Pestova TV. Activities of Ligatin and MCT-1/DENR in eukaryotic translation initiation and ribosomal recycling. Genes Dev. 2010 Aug 15;24(16):1787-801. doi: 10.1101/gad.1957510. PMID:20713520 doi:http://dx.doi.org/10.1101/gad.1957510
- ↑ Vaidya AT, Lomakin IB, Joseph NN, Dmitriev SE, Steitz TA. Crystal Structure of the C-terminal Domain of Human eIF2D and its Implications on Eukaryotic Translation Initiation. J Mol Biol. 2017 Jul 20. pii: S0022-2836(17)30352-2. doi:, 10.1016/j.jmb.2017.07.015. PMID:28736176 doi:http://dx.doi.org/10.1016/j.jmb.2017.07.015
