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| ==Evidence for a Dual Role of an Active Site Histidine in alpha-Amino-beta-Carboxymuconate-epsilon-Semialdehyde Decarboxylase== | | ==Evidence for a Dual Role of an Active Site Histidine in alpha-Amino-beta-Carboxymuconate-epsilon-Semialdehyde Decarboxylase== |
| <StructureSection load='4eri' size='340' side='right' caption='[[4eri]], [[Resolution|resolution]] 2.00Å' scene=''> | | <StructureSection load='4eri' size='340' side='right'caption='[[4eri]], [[Resolution|resolution]] 2.00Å' scene=''> |
| == Structural highlights == | | == Structural highlights == |
| <table><tr><td colspan='2'>[[4eri]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacillus_fluorescens_liquefaciens"_flugge_1886 "bacillus fluorescens liquefaciens" flugge 1886]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4ERI OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4ERI FirstGlance]. <br> | | <table><tr><td colspan='2'>[[4eri]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Pseudomonas_fluorescens Pseudomonas fluorescens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4ERI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4ERI FirstGlance]. <br> |
| </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</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]] 2.0006Å</td></tr> |
| <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4epk|4epk]], [[4era|4era]], [[4erg|4erg]]</td></tr> | | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr> |
| <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">nbaD ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=294 "Bacillus fluorescens liquefaciens" Flugge 1886])</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=4eri FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4eri OCA], [https://pdbe.org/4eri PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4eri RCSB], [https://www.ebi.ac.uk/pdbsum/4eri PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4eri ProSAT]</span></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=4eri FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4eri OCA], [http://pdbe.org/4eri PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4eri RCSB], [http://www.ebi.ac.uk/pdbsum/4eri PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4eri ProSAT]</span></td></tr> | |
| </table> | | </table> |
| <div style="background-color:#fffaf0;">
| | == Function == |
| == Publication Abstract from PubMed ==
| | [https://www.uniprot.org/uniprot/Q83V25_PSEFL Q83V25_PSEFL] |
| The previously reported crystal structures of alpha-amino-beta-carboxymuconate-epsilon-semialdehyde decarboxylase (ACMSD) show a five-coordinate Zn(II)(His)(3)(Asp)(OH(2)) active site. The water ligand is H-bonded to a conserved His228 residue adjacent to the metal center in ACMSD from Pseudomonas fluorescens (PfACMSD). Site-directed mutagenesis of His228 to tyrosine and glycine in this study results in a complete or significant loss of activity. Metal analysis shows that H228Y and H228G contain iron rather than zinc, indicating that this residue plays a role in the metal selectivity of the protein. As-isolated H228Y displays a blue color, which is not seen in wild-type ACMSD. Quinone staining and resonance Raman analyses indicate that the blue color originates from Fe(III)-tyrosinate ligand-to-metal charge transfer. Co(II)-substituted H228Y ACMSD is brown in color and exhibits an electron paramagnetic resonance spectrum showing a high-spin Co(II) center with a well-resolved (59)Co (I = (7)/(2)) eight-line hyperfine splitting pattern. The X-ray crystal structures of as-isolated Fe-H228Y (2.8 A) and Co-substituted (2.4 A) and Zn-substituted H228Y (2.0 A resolution) support the spectroscopic assignment of metal ligation of the Tyr228 residue. The crystal structure of Zn-H228G (2.6 A) was also determined. These four structures show that the water ligand present in WT Zn-ACMSD is either missing (Fe-H228Y, Co-H228Y, and Zn-H228G) or disrupted (Zn-H228Y) in response to the His228 mutation. Together, these results highlight the importance of His228 for PfACMSD's metal specificity as well as maintaining a water molecule as a ligand of the metal center. His228 is thus proposed to play a role in activating the metal-bound water ligand for subsequent nucleophilic attack on the substrate.
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| Evidence for a Dual Role of an Active Site Histidine in alpha-Amino-beta-carboxymuconate-epsilon-semialdehyde Decarboxylase.,Huo L, Fielding AJ, Chen Y, Li T, Iwaki H, Hosler JP, Chen L, Hasegawa Y, Que L Jr, Liu A Biochemistry. 2012 Jul 24;51(29):5811-21. Epub 2012 Jul 12. PMID:22746257<ref>PMID:22746257</ref>
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| From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
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| </div>
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| <div class="pdbe-citations 4eri" style="background-color:#fffaf0;"></div>
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| == References ==
| |
| <references/>
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| __TOC__ | | __TOC__ |
| </StructureSection> | | </StructureSection> |
| [[Category: Bacillus fluorescens liquefaciens flugge 1886]] | | [[Category: Large Structures]] |
| [[Category: Chen, L]] | | [[Category: Pseudomonas fluorescens]] |
| [[Category: Chen, Y]] | | [[Category: Chen L]] |
| [[Category: Fielding, A J]] | | [[Category: Chen Y]] |
| [[Category: Hasegawa, Y]] | | [[Category: Fielding AJ]] |
| [[Category: Hosler, J P]] | | [[Category: Hasegawa Y]] |
| [[Category: Huo, L]] | | [[Category: Hosler JP]] |
| [[Category: Iwaki, H]] | | [[Category: Huo L]] |
| [[Category: Li, T]] | | [[Category: Iwaki H]] |
| [[Category: Liu, A]] | | [[Category: Li T]] |
| [[Category: Que, L]] | | [[Category: Liu A]] |
| [[Category: Decarboxylase]]
| | [[Category: Que Jr L]] |
| [[Category: Lyase]]
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| [[Category: Metal-binding]]
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| [[Category: Tim barrel]]
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| [[Category: Zn]]
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