2DE4

Crystal structure of DSZB C27S mutant in complex with biphenyl-2-sulfinic acid

2DE4 の概要

• エントリーDOI: 10.2210/pdb2de4/pdb
• 関連するPDBエントリー: 2DE2 2DE3
• 分子名称: DIBENZOTHIOPHENE DESULFURIZATION ENZYME B, ACETATE ION, 1,1'-BIPHENYL-2-SULFINIC ACID, ... (4 entities in total)
• 機能のキーワード: alpha-beta, hydrolase
• 由来する生物種: Rhodococcus sp.
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 78679.62

構造登録者

Lee, W.C.,Ohshiro, T.,Matsubara, T.,Izumi, Y.,Tanokura, M. (登録日: 2006-02-08, 公開日: 2006-08-01, 最終更新日: 2024-05-29)

主引用文献

Lee, W.C.,Ohshiro, T.,Matsubara, T.,Izumi, Y.,Tanokura, M.
Crystal structure and desulfurization mechanism of 2'-hydroxybiphenyl-2-sulfinic acid desulfinase.
J.Biol.Chem., 281:32534-32539, 2006

PubMed Abstract: The desulfurization of dibenzothiophene in Rhodococcus erythropolis is catalyzed by two monooxygenases, DszA and DszC, and a desulfinase, DszB. In the last step of this pathway, DszB hydrolyzes 2'-hydroxybiphenyl-2-sulfinic acid into 2-hydroxybiphenyl and sulfite. We report on the crystal structures of DszB and an inactive mutant of DszB in complex with substrates at resolutions of 1.8A or better. The overall fold of DszB is similar to those of periplasmic substrate-binding proteins. In the substrate complexes, biphenyl rings of substrates are recognized by extensive hydrophobic interactions with the active site residues. Binding of substrates accompanies structural changes of the active site loops and recruits His(60) to the active site. The sulfinate group of bound substrates forms hydrogen bonds with side chains of Ser(27), His(60), and Arg(70), each of which is shown by site-directed mutagenesis to be essential for the activity. In our proposed reaction mechanism, Cys(27) functions as a nucleophile and seems to be activated by the sulfinate group of substrates, whereas His(60) and Arg(70) orient the syn orbital of sulfinate oxygen to the sulfhydryl hydrogen of Cys(27) and stabilize the negatively charged reaction intermediate. Cys, His, and Arg residues are conserved in putative proteins homologous to DszB, which are presumed to constitute a new family of desulfinases.

PubMed: 16891315
DOI: 10.1074/jbc.M602974200

実験手法

X-RAY DIFFRACTION (1.8 Å)