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| | <StructureSection load='6i2q' size='340' side='right'caption='[[6i2q]], [[Resolution|resolution]] 2.15Å' scene=''> | | <StructureSection load='6i2q' size='340' side='right'caption='[[6i2q]], [[Resolution|resolution]] 2.15Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[6i2q]] is a 2 chain structure. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=2xt9 2xt9]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6I2Q OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6I2Q FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[6i2q]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Mycolicibacterium_smegmatis_MC2_155 Mycolicibacterium smegmatis MC2 155]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=2xt9 2xt9]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6I2Q OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6I2Q FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=TPP:THIAMINE+DIPHOSPHATE'>TPP</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.15Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[2xt9|2xt9]]</td></tr>
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=TPP:THIAMINE+DIPHOSPHATE'>TPP</scene></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6i2q FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6i2q OCA], [http://pdbe.org/6i2q PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6i2q RCSB], [http://www.ebi.ac.uk/pdbsum/6i2q PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6i2q 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=6i2q FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6i2q OCA], [https://pdbe.org/6i2q PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6i2q RCSB], [https://www.ebi.ac.uk/pdbsum/6i2q PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6i2q ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/KGD_MYCS2 KGD_MYCS2]] Shows three enzymatic activities that share a first common step, the attack of thiamine-PP on 2-oxoglutarate (alpha-ketoglutarate, KG), leading to the formation of an enamine-thiamine-PP intermediate upon decarboxylation. Thus, displays KGD activity, catalyzing the decarboxylation from five-carbon 2-oxoglutarate to four-carbon succinate semialdehyde (SSA). Also catalyzes C-C bond formation between the activated aldehyde formed after decarboxylation of alpha-ketoglutarate and the carbonyl of glyoxylate (GLX), to yield 2-hydroxy-3-oxoadipate (HOA), which spontaneously decarboxylates to form 5-hydroxylevulinate (HLA). And is also a component of the 2-oxoglutarate dehydrogenase (ODH) complex, that catalyzes the overall conversion of 2-oxoglutarate to succinyl-CoA and CO(2). The KG decarboxylase and KG dehydrogenase reactions provide two alternative, tightly regulated, pathways connecting the oxidative and reductive branches of the TCA cycle.<ref>PMID:19019160</ref> <ref>PMID:21867916</ref> [[http://www.uniprot.org/uniprot/GARA_MYCS2 GARA_MYCS2]] Involved in regulation of glutamate metabolism. Acts as a phosphorylation-dependent molecular switch that modulates the activities of Kgd and Gdh.<ref>PMID:19019160</ref> | + | [https://www.uniprot.org/uniprot/GARA_MYCS2 GARA_MYCS2] Involved in regulation of glutamate metabolism. Acts as a phosphorylation-dependent molecular switch that modulates the activities of Kgd and Gdh.<ref>PMID:19019160</ref> |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | </StructureSection> | | </StructureSection> |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Alzari, P M]] | + | [[Category: Mycolicibacterium smegmatis MC2 155]] |
| - | [[Category: Bellinzoni, M]] | + | [[Category: Alzari PM]] |
| - | [[Category: Wagner, T]] | + | [[Category: Bellinzoni M]] |
| - | [[Category: Decarboxylase]] | + | [[Category: Wagner T]] |
| - | [[Category: Oxidoreductase]]
| + | |
| - | [[Category: Oxoglutarate dehydrogenase]]
| + | |
| Structural highlights
Function
GARA_MYCS2 Involved in regulation of glutamate metabolism. Acts as a phosphorylation-dependent molecular switch that modulates the activities of Kgd and Gdh.[1]
Publication Abstract from PubMed
Forkhead-associated (FHA) domains are modules that bind to phosphothreonine (pThr) residues in signaling cascades. The FHA-containing mycobacterial protein GarA is a central element of a phosphorylation-dependent signaling pathway that redirects metabolic flux in response to amino acid starvation or cell growth requirements. GarA acts as a phosphorylation-dependent ON/OFF molecular switch. In its nonphosphorylated ON state, the GarA FHA domain engages in phosphorylation-independent interactions with various metabolic enzymes that orchestrate nitrogen flow, such as 2-oxoglutarate decarboxylase (KGD). However, phosphorylation at the GarA N-terminal region by the protein kinase PknB or PknG triggers autoinhibition through the intramolecular association of the N-terminal domain with the FHA domain, thus blocking all downstream interactions. To investigate these different FHA binding modes, we solved the crystal structures of the mycobacterial upstream (phosphorylation-dependent) complex PknB-GarA and the downstream (phosphorylation-independent) complex GarA-KGD. Our results show that the phosphorylated activation loop of PknB serves as a docking site to recruit GarA through canonical FHA-pThr interactions. However, the same GarA FHA-binding pocket targets an allosteric site on nonphosphorylated KGD, where a key element of recognition is a phosphomimetic aspartate. Further enzymatic and mutagenesis studies revealed that GarA acted as a dynamic allosteric inhibitor of KGD by preventing crucial motions in KGD that are necessary for catalysis. Our results provide evidence for physiological phosphomimetics, supporting numerous mutagenesis studies using such approaches, and illustrate how evolution can shape a single FHA-binding pocket to specifically interact with multiple phosphorylated and nonphosphorylated protein partners.
Structural insights into the functional versatility of an FHA domain protein in mycobacterial signaling.,Wagner T, Andre-Leroux G, Hindie V, Barilone N, Lisa MN, Hoos S, Raynal B, Vulliez-Le Normand B, O'Hare HM, Bellinzoni M, Alzari PM Sci Signal. 2019 May 7;12(580). pii: 12/580/eaav9504. doi:, 10.1126/scisignal.aav9504. PMID:31064884[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ O'Hare HM, Duran R, Cervenansky C, Bellinzoni M, Wehenkel AM, Pritsch O, Obal G, Baumgartner J, Vialaret J, Johnsson K, Alzari PM. Regulation of glutamate metabolism by protein kinases in mycobacteria. Mol Microbiol. 2008 Dec;70(6):1408-23. doi: 10.1111/j.1365-2958.2008.06489.x., Epub 2008 Oct 17. PMID:19019160 doi:http://dx.doi.org/10.1111/j.1365-2958.2008.06489.x
- ↑ Wagner T, Andre-Leroux G, Hindie V, Barilone N, Lisa MN, Hoos S, Raynal B, Vulliez-Le Normand B, O'Hare HM, Bellinzoni M, Alzari PM. Structural insights into the functional versatility of an FHA domain protein in mycobacterial signaling. Sci Signal. 2019 May 7;12(580). pii: 12/580/eaav9504. doi:, 10.1126/scisignal.aav9504. PMID:31064884 doi:http://dx.doi.org/10.1126/scisignal.aav9504
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