1q46
From Proteopedia
(New page: 200px<br /><applet load="1q46" size="450" color="white" frame="true" align="right" spinBox="true" caption="1q46, resolution 2.86Å" /> '''crystal structure of...) |
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| - | [[Image:1q46.gif|left|200px]]<br /><applet load="1q46" size=" | + | [[Image:1q46.gif|left|200px]]<br /><applet load="1q46" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1q46, resolution 2.86Å" /> | caption="1q46, resolution 2.86Å" /> | ||
'''crystal structure of the eIF2 alpha subunit from saccharomyces cerevisia'''<br /> | '''crystal structure of the eIF2 alpha subunit from saccharomyces cerevisia'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The alpha subunit of translation initiation factor 2 (eIF2alpha) is the | + | 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. |
==About this Structure== | ==About this Structure== | ||
| - | 1Q46 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae]. Full crystallographic information is available from [http:// | + | 1Q46 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1Q46 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Dhaliwal, S.]] | [[Category: Dhaliwal, S.]] | ||
| - | [[Category: Hoffman, D | + | [[Category: Hoffman, D W.]] |
[[Category: eif2]] | [[Category: eif2]] | ||
[[Category: initiation factor]] | [[Category: initiation factor]] | ||
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[[Category: translation]] | [[Category: translation]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:35:40 2008'' |
Revision as of 12:35, 21 February 2008
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crystal structure of the eIF2 alpha subunit from saccharomyces cerevisia
Overview
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.
About this Structure
1Q46 is a Single protein structure of sequence from Saccharomyces cerevisiae. Full crystallographic information is available from OCA.
Reference
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., Dhaliwal S, Hoffman DW, J Mol Biol. 2003 Nov 21;334(2):187-95. PMID:14607111
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