Structural highlights
Function
[TMOD_PSEME] Effector protein subunit of the multicomponent enzyme toluene-4-monooxygenase that hydroxylates toluene to form p-cresol. Required for optimal efficiency and specificity of the holoenzyme.[1] [2] [3] [TMOB_PSEME] Subunit T4moB of the multicomponent enzyme toluene-4-monooxygenase that hydroxylates toluene to form p-cresol.[4] [5] [TMOE_PSEME] Subunit of the multicomponent enzyme toluene-4-monooxygenase that hydroxylates toluene to form p-cresol.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
A diiron hydroxylase reaction typically begins by combination of O2 with a diferrous center to form reactive intermediates capable of hydrocarbon hydroxylation. In this natural cycle, reducing equivalents are provided by specific interactions with electron transfer proteins. The biological process can be bypassed by combining H2O2 with a diferric center, i.e., peroxide-shunt catalysis. Here we show that toluene 4-monooxygenase has a peroxide-shunt reaction that is approximately 600-fold slower than catalysis driven by biological electron transfer. However, the toluene 4-monooxygenase hydroxylase-effector protein complex was stable in the presence of 300 mM H2O2, suggesting overall benign effects of the exogenous oxidant on active site structure and function. The X-ray structure of the toluene 4-monooxygenase hydroxylase-effector protein complex determined from crystals soaked in H2O2 revealed a bound diatomic molecule, assigned to a cis-mu-1,2-peroxo bridge. This peroxo species resides in an active site position adjacent to the hydrogen-bonding substructure established by effector protein binding and faces into the distal cavity where substrate must bind during regiospecific aromatic ring hydroxylation catalysis. These results provide a new structural benchmark for how activated intermediates may be formed and dispatched during diiron hydroxylase catalysis.
Crystallographic and catalytic studies of the peroxide-shunt reaction in a diiron hydroxylase.,Bailey LJ, Fox BG Biochemistry. 2009 Sep 29;48(38):8932-9. PMID:19705873[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Hemmi H, Studts JM, Chae YK, Song J, Markley JL, Fox BG. Solution structure of the toluene 4-monooxygenase effector protein (T4moD). Biochemistry. 2001 Mar 27;40(12):3512-24. PMID:11297417
- ↑ Lountos GT, Mitchell KH, Studts JM, Fox BG, Orville AM. Crystal structures and functional studies of T4moD, the toluene 4-monooxygenase catalytic effector protein. Biochemistry. 2005 May 17;44(19):7131-42. PMID:15882052 doi:10.1021/bi047459g
- ↑ Bailey LJ, McCoy JG, Phillips GN Jr, Fox BG. Structural consequences of effector protein complex formation in a diiron hydroxylase. Proc Natl Acad Sci U S A. 2008 Dec 9;105(49):19194-8. Epub 2008 Nov 25. PMID:19033467
- ↑ Elsen NL, Bailey LJ, Hauser AD, Fox BG. Role for threonine 201 in the catalytic cycle of the soluble diiron hydroxylase toluene 4-monooxygenase. Biochemistry. 2009 May 12;48(18):3838-46. PMID:19290655 doi:10.1021/bi900144a
- ↑ Bailey LJ, Fox BG. Crystallographic and catalytic studies of the peroxide-shunt reaction in a diiron hydroxylase. Biochemistry. 2009 Sep 29;48(38):8932-9. PMID:19705873 doi:10.1021/bi901150a
- ↑ Bailey LJ, Fox BG. Crystallographic and catalytic studies of the peroxide-shunt reaction in a diiron hydroxylase. Biochemistry. 2009 Sep 29;48(38):8932-9. PMID:19705873 doi:10.1021/bi901150a
