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| | ==Structure of eIF2B-eIF2 (phosphorylated at Ser51) complex (model 1)== | | ==Structure of eIF2B-eIF2 (phosphorylated at Ser51) complex (model 1)== |
| - | <SX load='6qg0' size='340' side='right' viewer='molstar' caption='[[6qg0]], [[Resolution|resolution]] 4.20Å' scene=''> | + | <SX load='6qg0' size='340' side='right' viewer='molstar' caption='[[6qg0]], [[Resolution|resolution]] 4.15Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[6qg0]] is a 16 chain structure with sequence from [http://en.wikipedia.org/wiki/Baker's_yeast Baker's yeast]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6QG0 OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=6QG0 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[6qg0]] is a 16 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharomyces_cerevisiae_S288C Saccharomyces cerevisiae S288C]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6QG0 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6QG0 FirstGlance]. <br> |
| - | </td></tr><tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=SEP:PHOSPHOSERINE'>SEP</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 4.15Å</td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">GCN3, AAS2, TIF221, YKR026C ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=559292 Baker's yeast]), GCD7, TIF222, YLR291C, L8003.17 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=559292 Baker's yeast]), GCD1, TIF223, TRA3, YOR260W ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=559292 Baker's yeast]), GCD2, TIF224, YGR083C ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=559292 Baker's yeast]), GCD6, TIF225, YDR211W, YD8142.12, YD8142B.03 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=559292 Baker's yeast]), SUI2, TIF211, YJR007W, J1429 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=559292 Baker's yeast]), GCD11, TIF213, YER025W ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=559292 Baker's yeast]), SUI3, TIF212, YPL237W ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=559292 Baker's yeast])</td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SEP:PHOSPHOSERINE'>SEP</scene></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=6qg0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6qg0 OCA], [http://pdbe.org/6qg0 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6qg0 RCSB], [http://www.ebi.ac.uk/pdbsum/6qg0 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6qg0 ProSAT]</span></td></tr> | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=6qg0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6qg0 OCA], [https://pdbe.org/6qg0 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6qg0 RCSB], [https://www.ebi.ac.uk/pdbsum/6qg0 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6qg0 ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/IF2A_YEAST IF2A_YEAST]] eIF-2 functions in the early steps of protein synthesis by forming a ternary complex with GTP and initiator tRNA. This complex binds to a 40S ribosomal subunit, followed by mRNA binding to form a 43S preinitiation complex. Junction of the 60S ribosomal subunit to form the 80S initiation complex is preceded by hydrolysis of the GTP bound to eIF-2 and release of an eIF-2-GDP binary complex. In order for eIF-2 to recycle and catalyze another round of initiation, the GDP bound to eIF-2 must exchange with GTP by way of a reaction catalyzed by eIF-2B. [[http://www.uniprot.org/uniprot/EI2BG_YEAST EI2BG_YEAST]] Acts as essential component of the translation initiation factor 2B (eIF2-B or GCD complex), which catalyzes the exchange of eukaryotic initiation factor 2 (eIF-2)-bound GDP for GTP and is regulated by phosphorylated eIF-2. It activates the synthesis of GCN4 in yeast under amino acid starvation conditions by suppressing the inhibitory effects of multiple AUG codons present in the leader of GCN4 mRNA. It may promote either repression or activation of GCN4 expression depending on amino acid availability. GCD1 stabilizes the interaction between eIF-2 and GCD6 and stimulates the catalytic activity in vitro.<ref>PMID:8506384</ref> <ref>PMID:9472020</ref> [[http://www.uniprot.org/uniprot/IF2G_YEAST IF2G_YEAST]] eIF-2 functions in the early steps of protein synthesis by forming a ternary complex with GTP and initiator tRNA. This complex binds to a 40S ribosomal subunit, followed by mRNA binding to form a 43S preinitiation complex. Junction of the 60S ribosomal subunit to form the 80S initiation complex is preceded by hydrolysis of the GTP bound to eIF-2 and release of an eIF-2-GDP binary complex. In order for eIF-2 to recycle and catalyze another round of initiation, the GDP bound to eIF-2 must exchange with GTP by way of a reaction catalyzed by eIF-2B. [[http://www.uniprot.org/uniprot/EI2BB_YEAST EI2BB_YEAST]] Acts as a regulatory component of the translation initiation factor 2B (eIF2-B or GCD complex), which catalyzes the exchange of eukaryotic initiation factor 2 (eIF-2)-bound GDP for GTP and is regulated by phosphorylated eIF-2. It activates the synthesis of GCN4 in yeast under amino acid starvation conditions by suppressing the inhibitory effects of multiple AUG codons present in the leader of GCN4 mRNA. It may promote either repression or activation of GCN4 expression depending on amino acid availability. GCD6 and GCD7 repress GCN4 expression at the translational level by ensuring that ribosomes which have translated UORF1 will reinitiate at UORF2, -3, or -4 and thus fail to reach the GCN4 start site.<ref>PMID:8506384</ref> <ref>PMID:9472020</ref> [[http://www.uniprot.org/uniprot/IF2B_YEAST IF2B_YEAST]] eIF-2 functions in the early steps of protein synthesis by forming a ternary complex with GTP and initiator tRNA. This complex binds to a 40S ribosomal subunit, followed by mRNA binding to form a 43S preinitiation complex. Junction of the 60S ribosomal subunit to form the 80S initiation complex is preceded by hydrolysis of the GTP bound to eIF-2 and release of an eIF-2-GDP binary complex. In order for eIF-2 to recycle and catalyze another round of initiation, the GDP bound to eIF-2 must exchange with GTP by way of a reaction catalyzed by eIF-2B. [[http://www.uniprot.org/uniprot/EI2BA_YEAST EI2BA_YEAST]] Acts as a non-essential regulatory component of the translation initiation factor 2B (eIF2-B or GCD complex), which catalyzes the exchange of eukaryotic initiation factor 2 (eIF-2)-bound GDP for GTP and is regulated by phosphorylated eIF-2. It activates the synthesis of GCN4 in yeast under amino acid starvation conditions by suppressing the inhibitory effects of multiple AUG codons present in the leader of GCN4 mRNA. It may promote either repression or activation of GCN4 expression depending on amino acid availability. Modulation of GCN3 regulatory function in response to amino acid availability occurs post-translationally.<ref>PMID:8506384</ref> <ref>PMID:9472020</ref> [[http://www.uniprot.org/uniprot/EI2BD_YEAST EI2BD_YEAST]] Acts as essential component of the translation initiation factor 2B (eIF2-B or GCD complex), which catalyzes the exchange of eukaryotic initiation factor 2 (eIF-2)-bound GDP for GTP and is regulated by phosphorylated eIF-2. It activates the synthesis of GCN4 in yeast under amino acid starvation conditions by suppressing the inhibitory effects of multiple AUG codons present in the leader of GCN4 mRNA. It may promote either repression or activation of GCN4 expression depending on amino acid availability. GCD2 is also required for cell viability. Its function can partially be replaced by GCN3 under normal growth conditions in GCD2-defective mutants, under AA starvation conditions GCN3 is an antagonist (GCN4 translational activator).<ref>PMID:8506384</ref> <ref>PMID:9472020</ref> [[http://www.uniprot.org/uniprot/EI2BE_YEAST EI2BE_YEAST]] Acts as a catalytic component of the translation initiation factor 2B (eIF2-B or GCD complex), which catalyzes the exchange of eukaryotic initiation factor 2 (eIF-2)-bound GDP for GTP and is regulated by phosphorylated eIF-2. It activates the synthesis of GCN4 in yeast under amino acid starvation conditions by suppressing the inhibitory effects of multiple AUG codons present in the leader of GCN4 mRNA. It may promote either repression or activation of GCN4 expression depending on amino acid availability. GCD6 and GCD7 repress GCN4 expression at the translational level by ensuring that ribosomes which have translated UORF1 will reinitiate at UORF2, -3, or -4 and thus fail to reach the GCN4 start site.<ref>PMID:8506384</ref> <ref>PMID:9472020</ref> | + | [https://www.uniprot.org/uniprot/EI2BG_YEAST EI2BG_YEAST] Acts as essential component of the translation initiation factor 2B (eIF2-B or GCD complex), which catalyzes the exchange of eukaryotic initiation factor 2 (eIF-2)-bound GDP for GTP and is regulated by phosphorylated eIF-2. It activates the synthesis of GCN4 in yeast under amino acid starvation conditions by suppressing the inhibitory effects of multiple AUG codons present in the leader of GCN4 mRNA. It may promote either repression or activation of GCN4 expression depending on amino acid availability. GCD1 stabilizes the interaction between eIF-2 and GCD6 and stimulates the catalytic activity in vitro.<ref>PMID:8506384</ref> <ref>PMID:9472020</ref> |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | </div> | | </div> |
| | <div class="pdbe-citations 6qg0" style="background-color:#fffaf0;"></div> | | <div class="pdbe-citations 6qg0" style="background-color:#fffaf0;"></div> |
| | + | |
| | + | ==See Also== |
| | + | *[[Eukaryotic initiation factor 3D structures|Eukaryotic initiation factor 3D structures]] |
| | == References == | | == References == |
| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| | </SX> | | </SX> |
| - | [[Category: Baker's yeast]] | |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Gordiyenko, Y]] | + | [[Category: Saccharomyces cerevisiae S288C]] |
| - | [[Category: Llacer, J L]] | + | [[Category: Gordiyenko Y]] |
| - | [[Category: Ramakrishnan, V]] | + | [[Category: Llacer JL]] |
| - | [[Category: Eif2]] | + | [[Category: Ramakrishnan V]] |
| - | [[Category: Eif2 alpha]]
| + | |
| - | [[Category: Eif2b]]
| + | |
| - | [[Category: Gef]]
| + | |
| - | [[Category: Heat domain]]
| + | |
| - | [[Category: Initiation factor]]
| + | |
| - | [[Category: Integrated stress response]]
| + | |
| - | [[Category: Isr]]
| + | |
| - | [[Category: Phosphorylation]]
| + | |
| - | [[Category: Translation]]
| + | |
| - | [[Category: Trnai]]
| + | |
