The crystal structure of the N-terminal region of the alpha subunit of translation initiation factor 2 (eIF2alpha) from Saccharomyces cerevisiae provides a view of the loop containing serine 51, the target of the eIF2alpha-specific kinases
- PMID: 14607111
- DOI: 10.1016/j.jmb.2003.09.045
The crystal structure of the N-terminal region of the alpha subunit of translation initiation factor 2 (eIF2alpha) from Saccharomyces cerevisiae provides a view of the loop containing serine 51, the target of the eIF2alpha-specific kinases
Abstract
The alpha subunit of translation initiation factor 2 (eIF2alpha) is the target of specific kinases that can phosphorylate a conserved serine residue as part of a mechanism for regulating protein expression at the translational level in eukaryotes. The structure of the 20 kDa N-terminal region of eIF2alpha from Saccharomyces cerevisiae was determined by X-ray crystallography at 2.5A resolution. In most respects, the structure is similar to that of the recently solved human eIF2alpha; the rather elongated protein contains a five-stranded antiparallel beta-barrel in its N-terminal region, followed by an almost entirely helical domain. The S.cerevisiae eIF2alpha lacks a disulfide bridge that is present in the homologous protein in humans and some of the other higher eukaryotes. Interestingly, a conserved loop consisting of residues 51-65 and containing serine 51, the putative phosphorylation site, is visible in the electron density maps of the S.cerevisiae eIF2alpha; most of this functionally important loop was not observed in the crystal structure of the human protein. This loop is relatively exposed to solvent, and contains two short 3(10) helices in addition to some extended structure. Serine 51 is located at the C-terminal end of one of the 3(10) helices and near several conserved positively charged residues. The side-chain of serine 51 is sufficiently exposed so that its phosphorylation would not necessitate a substantial change in the protein structure. The structures and relative positions of residues that have been implicated in kinase binding and in the interaction with guanine nucleotide exchange factor (eIF2B) are described.
Similar articles
-
PKR and GCN2 kinases and guanine nucleotide exchange factor eukaryotic translation initiation factor 2B (eIF2B) recognize overlapping surfaces on eIF2alpha.Mol Cell Biol. 2005 Apr;25(8):3063-75. doi: 10.1128/MCB.25.8.3063-3075.2005. Mol Cell Biol. 2005. PMID: 15798194 Free PMC article.
-
Crystal structure of the N-terminal segment of human eukaryotic translation initiation factor 2alpha.J Biol Chem. 2002 May 10;277(19):17057-61. doi: 10.1074/jbc.M111804200. Epub 2002 Feb 21. J Biol Chem. 2002. PMID: 11859078
-
Phosphorylation of translation initiation factor eIF2α at Ser51 depends on site- and context-specific information.FEBS Lett. 2018 Sep;592(18):3116-3125. doi: 10.1002/1873-3468.13214. Epub 2018 Sep 19. FEBS Lett. 2018. PMID: 30070006 Free PMC article.
-
Crystal structure of eIF2B and insights into eIF2-eIF2B interactions.FEBS J. 2017 Mar;284(6):868-874. doi: 10.1111/febs.13896. Epub 2016 Sep 29. FEBS J. 2017. PMID: 27627185 Review.
-
PKR and eIF2alpha: integration of kinase dimerization, activation, and substrate docking.Cell. 2005 Sep 23;122(6):823-5. doi: 10.1016/j.cell.2005.09.007. Cell. 2005. PMID: 16179248 Review.
Cited by
-
Evolutionary engineering improves tolerance for medium-chain alcohols in Saccharomyces cerevisiae.Biotechnol Biofuels. 2018 Apr 2;11:90. doi: 10.1186/s13068-018-1089-9. eCollection 2018. Biotechnol Biofuels. 2018. PMID: 29619086 Free PMC article.
-
The Jigsaw Puzzle of mRNA Translation Initiation in Eukaryotes: A Decade of Structures Unraveling the Mechanics of the Process.Annu Rev Biophys. 2018 May 20;47:125-151. doi: 10.1146/annurev-biophys-070816-034034. Epub 2018 Mar 1. Annu Rev Biophys. 2018. PMID: 29494255 Free PMC article.
-
Investigation of the Relationship between the S1 Domain and Its Molecular Functions Derived from Studies of the Tertiary Structure.Molecules. 2019 Oct 13;24(20):3681. doi: 10.3390/molecules24203681. Molecules. 2019. PMID: 31614904 Free PMC article.
-
Residues required for phosphorylation of translation initiation factor eIF2α under diverse stress conditions are divergent between yeast and human.Int J Biochem Cell Biol. 2015 Feb;59:135-41. doi: 10.1016/j.biocel.2014.12.004. Epub 2014 Dec 22. Int J Biochem Cell Biol. 2015. PMID: 25541374 Free PMC article.
-
Systematic genetic characterization of the human PKR kinase domain highlights its functional malleability to escape a poxvirus substrate mimic.bioRxiv [Preprint]. 2024 Sep 22:2024.05.29.596416. doi: 10.1101/2024.05.29.596416. bioRxiv. 2024. Update in: Elife. 2024 Nov 12;13:RP99575. doi: 10.7554/eLife.99575. PMID: 38903081 Free PMC article. Updated. Preprint.
Publication types
MeSH terms
Substances
Associated data
- Actions
LinkOut - more resources
Full Text Sources
Molecular Biology Databases