| Structural highlights
3n20 is a 3 chain structure with sequence from Pseudomonas sp. ox1. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Ligands: | FE, GOL, P6G |
| Related: | 1t0q, 2inc, 2ind, 2rdb, 3n1y, 3n1z, 3n1x |
| Gene: | touA (Pseudomonas sp. OX1), touE (Pseudomonas sp. OX1), touB (Pseudomonas sp. OX1) |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
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[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Song WJ, McCormick MS, Behan RK, Sazinsky MH, Jiang W, Lin J, Krebs C, Lippard SJ. Active site threonine facilitates proton transfer during dioxygen activation at the diiron center of toluene/o-xylene monooxygenase hydroxylase. J Am Chem Soc. 2010 Oct 6;132(39):13582-5. PMID:20839885 doi:10.1021/ja1063795
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