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| | <StructureSection load='6a19' size='340' side='right'caption='[[6a19]], [[Resolution|resolution]] 1.55Å' scene=''> | | <StructureSection load='6a19' size='340' side='right'caption='[[6a19]], [[Resolution|resolution]] 1.55Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[6a19]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/"streptomyces_orientalis"_pittenger_and_brigham_1956 "streptomyces orientalis" pittenger and brigham 1956]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6A19 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6A19 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[6a19]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Amycolatopsis_orientalis Amycolatopsis orientalis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6A19 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6A19 FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=173:BENZOYL-FORMIC+ACID'>173</scene>, <scene name='pdbligand=FMN:FLAVIN+MONONUCLEOTIDE'>FMN</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]] 1.55Å</td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">hmo ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=31958 "Streptomyces orientalis" Pittenger and Brigham 1956])</td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=173:BENZOYL-FORMIC+ACID'>173</scene>, <scene name='pdbligand=FMN:FLAVIN+MONONUCLEOTIDE'>FMN</scene></td></tr> |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/4-hydroxymandelate_oxidase 4-hydroxymandelate oxidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.3.46 1.1.3.46] </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=6a19 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6a19 OCA], [https://pdbe.org/6a19 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6a19 RCSB], [https://www.ebi.ac.uk/pdbsum/6a19 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6a19 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=6a19 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6a19 OCA], [http://pdbe.org/6a19 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6a19 RCSB], [http://www.ebi.ac.uk/pdbsum/6a19 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6a19 ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/HMO_AMYOR HMO_AMYOR]] Catalyzes the oxidation of p-hydroxymandelate to p-hydroxybenzoylformate in the biosynthesis of L-(4-hydroxyphenyl)glycine and L-(3,5-dihydroxyphenyl)glycine, 2 non-proteinogenic amino acids occurring in the vancomycin group of antibiotics.<ref>PMID:11137816</ref> <ref>PMID:12240298</ref> | + | [https://www.uniprot.org/uniprot/HMO_AMYOR HMO_AMYOR] Catalyzes the oxidation of p-hydroxymandelate to p-hydroxybenzoylformate in the biosynthesis of L-(4-hydroxyphenyl)glycine and L-(3,5-dihydroxyphenyl)glycine, 2 non-proteinogenic amino acids occurring in the vancomycin group of antibiotics.<ref>PMID:11137816</ref> <ref>PMID:12240298</ref> |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
| - | p-Hydroxymandelate oxidase (Hmo) is a flavin mononucleotide (FMN)-dependent enzyme that oxidizes mandelate to benzoylformate. How the FMN-dependent oxidation is executed by Hmo remains unclear at the molecular level. A continuum of snapshots from crystal structures of Hmo and its mutants in complex with physiological/nonphysiological substrates, products and inhibitors provides a rationale for its substrate enantioselectivity/promiscuity, its active-site geometry/reactivity and its direct hydride-transfer mechanism. A single mutant, Y128F, that extends the two-electron oxidation reaction to a four-electron oxidative decarboxylation reaction was unexpectedly observed. Biochemical and structural approaches, including biochemistry, kinetics, stable isotope labeling and X-ray crystallography, were exploited to reach these conclusions and provide additional insights. | + | The Y128F single mutant of p-hydroxymandelate oxidase (Hmo) is capable of oxidizing mandelate to benzoate via a four-electron oxidative decarboxylation reaction. When benzoylformate (the product of the first two-electron oxidation) and hydrogen peroxide (an oxidant) were used as substrates the reaction did not proceed, suggesting that free hydrogen peroxide is not the committed oxidant in the second two-electron oxidation. How the flavin mononucleotide (FMN)-dependent four-electron oxidation reaction takes place remains elusive. Structural and biochemical explorations have shed new light on this issue. 15 high-resolution crystal structures of Hmo and its mutants liganded with or without a substrate reveal that oxidized FMN (FMNox) possesses a previously unknown electrophilic/nucleophilic duality. In the Y128F mutant the active-site perturbation ensemble facilitates the polarization of FMNox to a nucleophilic ylide, which is in a position to act on an alpha-ketoacid, forming an N5-acyl-FMNred dead-end adduct. In four-electron oxidation, an intramolecular disproportionation reaction via an N5-alkanol-FMNred C'alpha carbanion intermediate may account for the ThDP/PLP/NADPH-independent oxidative decarboxylation reaction. A synthetic 5-deaza-FMNox cofactor in combination with an alpha-hydroxyamide or alpha-ketoamide biochemically and structurally supports the proposed mechanism. |
| | | | |
| - | Biochemical and structural explorations of alpha-hydroxyacid oxidases reveal a four-electron oxidative decarboxylation reaction.,Yeh HW, Lin KH, Lyu SY, Li YS, Huang CM, Wang YL, Shih HW, Hsu NS, Wu CJ, Li TL Acta Crystallogr D Struct Biol. 2019 Aug 1;75(Pt 8):733-742. doi:, 10.1107/S2059798319009574. Epub 2019 Jul 30. PMID:31373572<ref>PMID:31373572</ref>
| + | The flavin mononucleotide cofactor in alpha-hydroxyacid oxidases exerts its electrophilic/nucleophilic duality in control of the substrate-oxidation level.,Lyu SY, Lin KH, Yeh HW, Li YS, Huang CM, Wang YL, Shih HW, Hsu NS, Wu CJ, Li TL Acta Crystallogr D Struct Biol. 2019 Oct 1;75(Pt 10):918-929. doi:, 10.1107/S2059798319011938. Epub 2019 Sep 24. PMID:31588923<ref>PMID:31588923</ref> |
| | | | |
| | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> |
| | </div> | | </div> |
| | <div class="pdbe-citations 6a19" style="background-color:#fffaf0;"></div> | | <div class="pdbe-citations 6a19" style="background-color:#fffaf0;"></div> |
| - | | |
| - | ==See Also== | |
| - | *[[Journal:Acta Cryst D:S2059798319009574|Journal:Acta Cryst D:S2059798319009574]] | |
| | == References == | | == References == |
| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Streptomyces orientalis pittenger and brigham 1956]] | + | [[Category: Amycolatopsis orientalis]] |
| - | [[Category: 4-hydroxymandelate oxidase]]
| + | |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Li, T L]] | + | [[Category: Li TL]] |
| - | [[Category: Lin, K H]] | + | [[Category: Lin KH]] |
| - | [[Category: Flavoprotein]]
| + | |
| - | [[Category: Fmn-dependent oxidase]]
| + | |
| Structural highlights
Function
HMO_AMYOR Catalyzes the oxidation of p-hydroxymandelate to p-hydroxybenzoylformate in the biosynthesis of L-(4-hydroxyphenyl)glycine and L-(3,5-dihydroxyphenyl)glycine, 2 non-proteinogenic amino acids occurring in the vancomycin group of antibiotics.[1] [2]
Publication Abstract from PubMed
The Y128F single mutant of p-hydroxymandelate oxidase (Hmo) is capable of oxidizing mandelate to benzoate via a four-electron oxidative decarboxylation reaction. When benzoylformate (the product of the first two-electron oxidation) and hydrogen peroxide (an oxidant) were used as substrates the reaction did not proceed, suggesting that free hydrogen peroxide is not the committed oxidant in the second two-electron oxidation. How the flavin mononucleotide (FMN)-dependent four-electron oxidation reaction takes place remains elusive. Structural and biochemical explorations have shed new light on this issue. 15 high-resolution crystal structures of Hmo and its mutants liganded with or without a substrate reveal that oxidized FMN (FMNox) possesses a previously unknown electrophilic/nucleophilic duality. In the Y128F mutant the active-site perturbation ensemble facilitates the polarization of FMNox to a nucleophilic ylide, which is in a position to act on an alpha-ketoacid, forming an N5-acyl-FMNred dead-end adduct. In four-electron oxidation, an intramolecular disproportionation reaction via an N5-alkanol-FMNred C'alpha carbanion intermediate may account for the ThDP/PLP/NADPH-independent oxidative decarboxylation reaction. A synthetic 5-deaza-FMNox cofactor in combination with an alpha-hydroxyamide or alpha-ketoamide biochemically and structurally supports the proposed mechanism.
The flavin mononucleotide cofactor in alpha-hydroxyacid oxidases exerts its electrophilic/nucleophilic duality in control of the substrate-oxidation level.,Lyu SY, Lin KH, Yeh HW, Li YS, Huang CM, Wang YL, Shih HW, Hsu NS, Wu CJ, Li TL Acta Crystallogr D Struct Biol. 2019 Oct 1;75(Pt 10):918-929. doi:, 10.1107/S2059798319011938. Epub 2019 Sep 24. PMID:31588923[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Hubbard BK, Thomas MG, Walsh CT. Biosynthesis of L-p-hydroxyphenylglycine, a non-proteinogenic amino acid constituent of peptide antibiotics. Chem Biol. 2000 Dec;7(12):931-42. PMID:11137816
- ↑ Li TL, Choroba OW, Charles EH, Sandercock AM, Williams DH, Spencer JB. Characterisation of a hydroxymandelate oxidase involved in the biosynthesis of two unusual amino acids occurring in the vancomycin group of antibiotics. Chem Commun (Camb). 2001 Sep 21;(18):1752-3. PMID:12240298
- ↑ Lyu SY, Lin KH, Yeh HW, Li YS, Huang CM, Wang YL, Shih HW, Hsu NS, Wu CJ, Li TL. The flavin mononucleotide cofactor in alpha-hydroxyacid oxidases exerts its electrophilic/nucleophilic duality in control of the substrate-oxidation level. Acta Crystallogr D Struct Biol. 2019 Oct 1;75(Pt 10):918-929. doi:, 10.1107/S2059798319011938. Epub 2019 Sep 24. PMID:31588923 doi:http://dx.doi.org/10.1107/S2059798319011938
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