3n20: Difference between revisions
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== | ==X-ray Crystal Structure of Toluene/o-Xylene Monooxygenase Hydroxylase T201V Mutant== | ||
[[3n20]] is a 3 chain structure with sequence from [ | <StructureSection load='3n20' size='340' side='right'caption='[[3n20]], [[Resolution|resolution]] 1.90Å' scene=''> | ||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[3n20]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Pseudomonas_sp._OX1 Pseudomonas sp. OX1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3N20 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3N20 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]] 1.9Å</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>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=P6G:HEXAETHYLENE+GLYCOL'>P6G</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=3n20 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3n20 OCA], [https://pdbe.org/3n20 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3n20 RCSB], [https://www.ebi.ac.uk/pdbsum/3n20 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3n20 ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/Q6IV66_9PSED Q6IV66_9PSED] | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Toluene/o-xylene monooxygenase hydroxylase (ToMOH), a diiron-containing enzyme, can activate dioxygen to oxidize aromatic substrates. To elucidate the role of a strictly conserved T201 residue during dioxygen activation of the enzyme, T201S, T201G, T201C, and T201V variants of ToMOH were prepared by site-directed mutagenesis. X-ray crystal structures of all the variants were obtained. Steady-state activity, regiospecificity, and single-turnover yields were also determined for the T201 mutants. Dioxygen activation by the reduced T201 variants was explored by stopped-flow UV-vis and Mossbauer spectroscopy. These studies demonstrate that the dioxygen activation mechanism is preserved in all T201 variants; however, both the formation and decay kinetics of a peroxodiiron(III) intermediate, T201(peroxo), were greatly altered, revealing that T201 is critically involved in dioxygen activation. A comparison of the kinetics of O(2) activation in the T201S, T201C, and T201G variants under various reaction conditions revealed that T201 plays a major role in proton transfer, which is required to generate the peroxodiiron(III) intermediate. A mechanism is postulated for dioxygen activation, and possible structures of oxygenated intermediates are discussed. | |||
Active site threonine facilitates proton transfer during dioxygen activation at the diiron center of toluene/o-xylene monooxygenase hydroxylase.,Song WJ, McCormick MS, Behan RK, Sazinsky MH, Jiang W, Lin J, Krebs C, Lippard SJ J Am Chem Soc. 2010 Oct 6;132(39):13582-5. PMID:20839885<ref>PMID:20839885</ref> | |||
<ref | |||
[[ | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
</div> | |||
<div class="pdbe-citations 3n20" style="background-color:#fffaf0;"></div> | |||
[[Category: | ==See Also== | ||
[[Category: | *[[Monooxygenase 3D structures|Monooxygenase 3D structures]] | ||
[[Category: | == References == | ||
[[Category: | <references/> | ||
[[Category: | __TOC__ | ||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Pseudomonas sp. OX1]] | |||
[[Category: Lippard SJ]] | |||
[[Category: McCormick MS]] | |||
[[Category: Sazinsky MH]] | |||
Latest revision as of 12:07, 6 September 2023
X-ray Crystal Structure of Toluene/o-Xylene Monooxygenase Hydroxylase T201V MutantX-ray Crystal Structure of Toluene/o-Xylene Monooxygenase Hydroxylase T201V Mutant
Structural highlights
FunctionPublication Abstract from PubMedToluene/o-xylene monooxygenase hydroxylase (ToMOH), a diiron-containing enzyme, can activate dioxygen to oxidize aromatic substrates. To elucidate the role of a strictly conserved T201 residue during dioxygen activation of the enzyme, T201S, T201G, T201C, and T201V variants of ToMOH were prepared by site-directed mutagenesis. X-ray crystal structures of all the variants were obtained. Steady-state activity, regiospecificity, and single-turnover yields were also determined for the T201 mutants. Dioxygen activation by the reduced T201 variants was explored by stopped-flow UV-vis and Mossbauer spectroscopy. These studies demonstrate that the dioxygen activation mechanism is preserved in all T201 variants; however, both the formation and decay kinetics of a peroxodiiron(III) intermediate, T201(peroxo), were greatly altered, revealing that T201 is critically involved in dioxygen activation. A comparison of the kinetics of O(2) activation in the T201S, T201C, and T201G variants under various reaction conditions revealed that T201 plays a major role in proton transfer, which is required to generate the peroxodiiron(III) intermediate. A mechanism is postulated for dioxygen activation, and possible structures of oxygenated intermediates are discussed. Active site threonine facilitates proton transfer during dioxygen activation at the diiron center of toluene/o-xylene monooxygenase hydroxylase.,Song WJ, McCormick MS, Behan RK, Sazinsky MH, Jiang W, Lin J, Krebs C, Lippard SJ J Am Chem Soc. 2010 Oct 6;132(39):13582-5. PMID:20839885[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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