2isq: Difference between revisions

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OCA

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-[[Image:2isq.jpg|left|200px]]<br /><applet load="2isq" size="450" color="white" frame="true" align="right" spinBox="true"
-caption="2isq, resolution 2.8&Aring;" />
-'''Crystal Structure of O-Acetylserine Sulfhydrylase from Arabidopsis Thaliana in Complex with C-Terminal Peptide from Arabidopsis Serine Acetyltransferase'''<br />
-==Overview==
+==Crystal Structure of O-Acetylserine Sulfhydrylase from Arabidopsis Thaliana in Complex with C-Terminal Peptide from Arabidopsis Serine Acetyltransferase==
-In plants, association of O-acetylserine sulfhydrylase (OASS) and Ser, acetyltransferase (SAT) into the Cys synthase complex plays a regulatory, role in sulfur assimilation and Cys biosynthesis. We determined the, crystal structure of Arabidopsis thaliana OASS (At-OASS) bound with a, peptide corresponding to the C-terminal 10 residues of Arabidopsis SAT, (C10 peptide) at 2.9-A resolution. Hydrogen bonding interactions with key, active site residues (Thr-74, Ser-75, and Gln-147) lock the C10 peptide in, the binding site. C10 peptide binding blocks access to OASS catalytic, residues, explaining how complex formation downregulates OASS activity., Comparison with bacterial OASS suggests that structural plasticity in the, active site allows binding of SAT C termini with dissimilar sequences at, structurally similar OASS active sites. Calorimetric analysis of the, effect of active site mutations (T74S, S75A, S75T, and Q147A) demonstrates, that these residues are important for C10 peptide binding and that changes, at these positions disrupt communication between active sites in the, homodimeric enzyme. We also demonstrate that the C-terminal Ile of the C10, peptide is required for molecular recognition by At-OASS. These results, provide new insights into the molecular mechanism underlying formation of, the Cys synthase complex and provide a structural basis for the, biochemical regulation of Cys biosynthesis in plants.
+<StructureSection load='2isq' size='340' side='right'caption='[[2isq]], [[Resolution|resolution]] 2.80&Aring;' scene=''>
+== Structural highlights ==
+<table><tr><td colspan='2'>[[2isq]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Arabidopsis_thaliana Arabidopsis thaliana]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2ISQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2ISQ FirstGlance]. <br>
+</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.8&#8491;</td></tr>
+<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=PLP:PYRIDOXAL-5-PHOSPHATE'>PLP</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></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=2isq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2isq OCA], [https://pdbe.org/2isq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2isq RCSB], [https://www.ebi.ac.uk/pdbsum/2isq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2isq ProSAT]</span></td></tr>
+</table>
+== Function ==
+[https://www.uniprot.org/uniprot/CYSK1_ARATH CYSK1_ARATH]
+== Evolutionary Conservation ==
+[[Image:Consurf_key_small.gif|200px|right]]
+Check<jmol>
+  <jmolCheckbox>
+    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/is/2isq_consurf.spt"</scriptWhenChecked>
+    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
+    <text>to colour the structure by Evolutionary Conservation</text>
+  </jmolCheckbox>
+</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2isq ConSurf].
+<div style="clear:both"></div>
+<div style="background-color:#fffaf0;">
+== Publication Abstract from PubMed ==
+In plants, association of O-acetylserine sulfhydrylase (OASS) and Ser acetyltransferase (SAT) into the Cys synthase complex plays a regulatory role in sulfur assimilation and Cys biosynthesis. We determined the crystal structure of Arabidopsis thaliana OASS (At-OASS) bound with a peptide corresponding to the C-terminal 10 residues of Arabidopsis SAT (C10 peptide) at 2.9-A resolution. Hydrogen bonding interactions with key active site residues (Thr-74, Ser-75, and Gln-147) lock the C10 peptide in the binding site. C10 peptide binding blocks access to OASS catalytic residues, explaining how complex formation downregulates OASS activity. Comparison with bacterial OASS suggests that structural plasticity in the active site allows binding of SAT C termini with dissimilar sequences at structurally similar OASS active sites. Calorimetric analysis of the effect of active site mutations (T74S, S75A, S75T, and Q147A) demonstrates that these residues are important for C10 peptide binding and that changes at these positions disrupt communication between active sites in the homodimeric enzyme. We also demonstrate that the C-terminal Ile of the C10 peptide is required for molecular recognition by At-OASS. These results provide new insights into the molecular mechanism underlying formation of the Cys synthase complex and provide a structural basis for the biochemical regulation of Cys biosynthesis in plants.
-==About this Structure==
+Structural basis for interaction of O-acetylserine sulfhydrylase and serine acetyltransferase in the Arabidopsis cysteine synthase complex.,Francois JA, Kumaran S, Jez JM Plant Cell. 2006 Dec;18(12):3647-55. Epub 2006 Dec 28. PMID:17194764<ref>PMID:17194764</ref>
-ISQ is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Arabidopsis_thaliana Arabidopsis thaliana] with SO4 and PLP as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Cysteine_synthase Cysteine synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.47 2.5.1.47] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2ISQ OCA].
-==Reference==
+From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
-Structural basis for interaction of O-acetylserine sulfhydrylase and serine acetyltransferase in the Arabidopsis cysteine synthase complex., Francois JA, Kumaran S, Jez JM, Plant Cell. 2006 Dec;18(12):3647-55. Epub 2006 Dec 28. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17194764 17194764]
+</div>
+<div class="pdbe-citations 2isq" style="background-color:#fffaf0;"></div>
+== References ==
+<references/>
+__TOC__
+</StructureSection>
 [[Category: Arabidopsis thaliana]]
-[[Category: Cysteine synthase]]
+[[Category: Large Structures]]
-[[Category: Protein complex]]
+[[Category: Francois JA]]
-[[Category: Francois, J.A.]]
+[[Category: Jez JM]]
-[[Category: Jez, J.M.]]
+[[Category: Kumaran S]]
-[[Category: Kumaran, S.]]
-[[Category: PLP]]
-[[Category: SO4]]
-[[Category: alpha beta structrual domain]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 15:30:11 2007''