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1i86

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[[Image:1i86.jpg|left|200px]]
 
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==CHALCONE SYNTHASE, G256A MUTANT==
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The line below this paragraph, containing "STRUCTURE_1i86", creates the "Structure Box" on the page.
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<StructureSection load='1i86' size='340' side='right'caption='[[1i86]], [[Resolution|resolution]] 1.50&Aring;' scene=''>
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You may change the PDB parameter (which sets the PDB file loaded into the applet)
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== Structural highlights ==
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or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
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<table><tr><td colspan='2'>[[1i86]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Medicago_sativa Medicago sativa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1I86 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1I86 FirstGlance]. <br>
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or leave the SCENE parameter empty for the default display.
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</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.5&#8491;</td></tr>
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<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CSD:3-SULFINOALANINE'>CSD</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
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{{STRUCTURE_1i86| PDB=1i86 | SCENE= }}
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<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1i86 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1i86 OCA], [https://pdbe.org/1i86 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1i86 RCSB], [https://www.ebi.ac.uk/pdbsum/1i86 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1i86 ProSAT]</span></td></tr>
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</table>
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== Function ==
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[https://www.uniprot.org/uniprot/CHS2_MEDSA CHS2_MEDSA] The primary product of this enzyme is 4,2',4',6'-tetrahydroxychalcone (also termed naringenin-chalcone or chalcone) which can under specific conditions spontaneously isomerize into naringenin.<ref>PMID:10653632</ref> <ref>PMID:11732902</ref> <ref>PMID:11959984</ref> <ref>PMID:15380179</ref>
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== Evolutionary Conservation ==
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[[Image:Consurf_key_small.gif|200px|right]]
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Check<jmol>
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<jmolCheckbox>
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<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/i8/1i86_consurf.spt"</scriptWhenChecked>
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<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
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<text>to colour the structure by Evolutionary Conservation</text>
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</jmolCheckbox>
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</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=1i86 ConSurf].
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<div style="clear:both"></div>
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'''CHALCONE SYNTHASE, G256A MUTANT'''
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==See Also==
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*[[Chalcone synthase|Chalcone synthase]]
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== References ==
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==Overview==
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<references/>
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Chalcone synthase (CHS) belongs to the family of type III polyketide synthases (PKS) that catalyze formation of structurally diverse polyketides. CHS synthesizes a tetraketide by sequential condensation of three acetyl anions derived from malonyl-CoA decarboxylation to a p-coumaroyl moiety attached to an active site cysteine. Gly256 resides on the surface of the CHS active site that is in direct contact with the polyketide chain derived from malonyl-CoA. Thus, position 256 serves as an ideal target to probe the link between cavity volume and polyketide chain-length determination in type III PKS. Functional examination of CHS G256A, G256V, G256L, and G256F mutants reveals altered product profiles from that of wild-type CHS. With p-coumaroyl-CoA as a starter molecule, the G256A and G256V mutants produce notably more tetraketide lactone. Further restrictions in cavity volume such as that seen in the G256L and G256F mutants yield increasing levels of the styrylpyrone bis-noryangonin from a triketide intermediate. X-ray crystallographic structures of the CHS G256A, G256V, G256L, and G256F mutants establish that these substitutions reduce the size of the active site cavity without significant alterations in the conformations of the polypeptide backbones. The side chain volume of position 256 influences both the number of condensation reactions during polyketide chain extension and the conformation of the triketide and tetraketide intermediates during the cyclization reaction. These results viewed in conjunction with the natural sequence variation of residue 256 suggest that rapid diversification of product specificity without concomitant loss of substantial catalytic activity in related CHS-like enzymes can occur by site-specific evolution of side chain volume at position 256.
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__TOC__
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</StructureSection>
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==About this Structure==
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[[Category: Large Structures]]
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1I86 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Medicago_sativa Medicago sativa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1I86 OCA].
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==Reference==
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Structure-guided programming of polyketide chain-length determination in chalcone synthase., Jez JM, Bowman ME, Noel JP, Biochemistry. 2001 Dec 11;40(49):14829-38. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/11732902 11732902]
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[[Category: Medicago sativa]]
[[Category: Medicago sativa]]
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[[Category: Naringenin-chalcone synthase]]
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[[Category: Bowman ME]]
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[[Category: Single protein]]
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[[Category: Jez JM]]
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[[Category: Bowman, M E.]]
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[[Category: Noel JP]]
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[[Category: Jez, J M.]]
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[[Category: Noel, J P.]]
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[[Category: Chalcone synthase]]
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[[Category: Polyketide synthase]]
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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 19:41:41 2008''
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Current revision

CHALCONE SYNTHASE, G256A MUTANT

PDB ID 1i86

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