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| [[Image:1bou.gif|left|200px]]<br /><applet load="1bou" size="350" color="white" frame="true" align="right" spinBox="true"
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| caption="1bou, resolution 2.2Å" />
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| '''THREE-DIMENSIONAL STRUCTURE OF LIGAB'''<br />
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| ==Overview== | | ==THREE-DIMENSIONAL STRUCTURE OF LIGAB== |
| BACKGROUND: Sphingomonas paucimobilis SYK-6 utilizes an extradiol-type catecholic dioxygenase, the LigAB enzyme (a protocatechuate 4,5-dioxygenase), to oxidize protocatechuate (or 3,4-dihydroxybenzoic acid, PCA). The enzyme belongs to the family of class III extradiol-type catecholic dioxygenases catalyzing the ring-opening reaction of protocatechuate and related compounds. The primary structure of LigAB suggests that the enzyme has no evolutionary relationship with the family of class II extradiol-type catecholic dioxygenases. Both the class II and class III enzymes utilize a non-heme ferrous center for adding dioxygen to the substrate. By elucidating the structure of LigAB, we aimed to provide a structural basis for discussing the function of class III enzymes. RESULTS: The crystal structure of substrate-free LigAB was solved at 2.2 A resolution. The molecule is an alpha2beta2 tetramer. The active site contains a non-heme iron coordinated by His12, His61, Glu242, and a water molecule located in a deep cleft of the beta subunit, which is covered by the alpha subunit. Because of the apparent oxidation of the Fe ion into the nonphysiological Fe(III) state, we could also solve the structure of LigAB complexed with a substrate, PCA. The iron coordination sphere in this complex is a distorted tetragonal bipyramid with one ligand missing, which is presumed to be the O2-binding site. CONCLUSIONS: The structure of LigAB is completely different from those of the class II extradiol-type dioxygenases exemplified by the BphC enzyme, a 2,3-dihydroxybiphenyl 1,2-dioxygenase from a Pseudomonas species. Thus, as already implicated by the primary structures, no evolutionary relationship exists between the class II and III enzymes. However, the two classes of enzymes share many geometrical characteristics with respect to the nature of the iron coordination sphere and the position of a putative catalytic base, strongly suggesting a common catalytic mechanism.
| | <StructureSection load='1bou' size='340' side='right'caption='[[1bou]], [[Resolution|resolution]] 2.20Å' scene=''> |
| | == Structural highlights == |
| | <table><tr><td colspan='2'>[[1bou]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Sphingomonas_paucimobilis Sphingomonas paucimobilis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BOU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1BOU 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]] 2.2Å</td></tr> |
| | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FE:FE+(III)+ION'>FE</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=1bou FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1bou OCA], [https://pdbe.org/1bou PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1bou RCSB], [https://www.ebi.ac.uk/pdbsum/1bou PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1bou ProSAT]</span></td></tr> |
| | </table> |
| | == Function == |
| | [https://www.uniprot.org/uniprot/PCYA_SPHSK PCYA_SPHSK] |
| | == 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/bo/1bou_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=1bou ConSurf]. |
| | <div style="clear:both"></div> |
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| ==About this Structure== | | ==See Also== |
| 1BOU is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Sphingomonas_paucimobilis Sphingomonas paucimobilis] with <scene name='pdbligand=FE:'>FE</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Protocatechuate_4,5-dioxygenase Protocatechuate 4,5-dioxygenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.13.11.8 1.13.11.8] Known structural/functional Sites: <scene name='pdbsite=FEA:Active+Site'>FEA</scene> and <scene name='pdbsite=FEB:Active+Site'>FEB</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BOU OCA].
| | *[[Dioxygenase 3D structures|Dioxygenase 3D structures]] |
| | | __TOC__ |
| ==Reference==
| | </StructureSection> |
| Crystal structure of an aromatic ring opening dioxygenase LigAB, a protocatechuate 4,5-dioxygenase, under aerobic conditions., Sugimoto K, Senda T, Aoshima H, Masai E, Fukuda M, Mitsui Y, Structure. 1999 Aug 15;7(8):953-65. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=10467151 10467151]
| | [[Category: Large Structures]] |
| [[Category: Protein complex]]
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| [[Category: Protocatechuate 4,5-dioxygenase]] | |
| [[Category: Sphingomonas paucimobilis]] | | [[Category: Sphingomonas paucimobilis]] |
| [[Category: Fukuda, M.]] | | [[Category: Fukuda M]] |
| [[Category: Mitsui, Y.]] | | [[Category: Mitsui Y]] |
| [[Category: Senda, T.]] | | [[Category: Senda T]] |
| [[Category: Sugimoto, K.]] | | [[Category: Sugimoto K]] |
| [[Category: FE]]
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| [[Category: extradiol type dioxygenase]]
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| [[Category: oxidoreductase]]
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| ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:57:30 2008''
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