3HWC

Crystal Structure of Chlorophenol 4-Monooxygenase (TftD) of Burkholderia cepacia AC1100

3HWC の概要

• エントリーDOI: 10.2210/pdb3hwc/pdb
• 分子名称: Chlorophenol-4-monooxygenase component 2 (2 entities in total)
• 機能のキーワード: beta barrel, helix bundle, monooxygenase, oxidoreductase
• 由来する生物種: Burkholderia cepacia
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 230086.34

構造登録者

Ballinger, J.W.,Kang, C.H. (登録日: 2009-06-17, 公開日: 2009-11-10, 最終更新日: 2024-02-21)

主引用文献

Webb, B.N.,Ballinger, J.W.,Kim, E.,Belchik, S.M.,Lam, K.S.,Youn, B.,Nissen, M.S.,Xun, L.,Kang, C.
Characterization of chlorophenol 4-monooxygenase (TftD) and NADH:FAD oxidoreductase (TftC) of Burkholderia cepacia AC1100.
J.Biol.Chem., 285:2014-2027, 2010

PubMed Abstract: Burkholderia cepacia AC1100 completely degrades 2,4,5-trichlorophenol, in which an FADH(2)-dependent monooxygenase (TftD) and an NADH:FAD oxidoreductase (TftC) catalyze the initial steps. TftD oxidizes 2,4,5-trichlorophenol (2,4,5-TCP) to 2,5-dichloro-p-benzoquinone, which is chemically reduced to 2,5-dichloro-p-hydroquinone (2,5-DiCHQ). Then, TftD oxidizes the latter to 5-chloro-2-hydroxy-p-benzoquinone. In those processes, TftC provides all the required FADH(2). We have determined the crystal structures of dimeric TftC and tetrameric TftD at 2.0 and 2.5 A resolution, respectively. The structure of TftC was similar to those of related flavin reductases. The stacked nicotinamide:isoalloxazine rings in TftC and sequential reaction kinetics suggest that the reduced FAD leaves TftC after NADH oxidation. The structure of TftD was also similar to the known structures of FADH(2)-dependent monooxygenases. Its His-289 residue in the re-side of the isoalloxazine ring is within hydrogen bonding distance with a hydroxyl group of 2,5-DiCHQ. An H289A mutation resulted in the complete loss of activity toward 2,5-DiCHQ and a significant decrease in catalytic efficiency toward 2,4,5-TCP. Thus, His-289 plays different roles in the catalysis of 2,4,5-TCP and 2,5-DiCHQ. The results support that free FADH(2) is generated by TftC, and TftD uses FADH(2) to separately transform 2,4,5-TCP and 2,5-DiCHQ. Additional experimental data also support the diffusion of FADH(2) between TftC and TftD without direct physical interaction between the two enzymes.

PubMed: 19915006
DOI: 10.1074/jbc.M109.056135

実験手法

X-RAY DIFFRACTION (2.5 Å)