Structural basis of enzymatic activity for the ferulic acid decarboxylase (FADase) from Enterobacter sp. Px6-4.
Structural basis of enzymatic activity for the ferulic acid decarboxylase (FADase) from Enterobacter sp. Px6-4.
复制标题
DOI：
10.1371/journal.pone.0016262
复制
发表时间：
2011-01-21
期刊：
影响因子：
3.7
通讯作者：
Zhang KQ
中科院分区：
文献类型：
--
作者：
Gu W;Yang J;Lou Z;Liang L;Sun Y;Huang J;Li X;Cao Y;Meng Z;Zhang KQ
微生物阿魏酸脱羧酶（FADase）通过非氧化脱羧催化阿魏酸转化为4-羟基-3-甲氧基苯乙烯（4-乙烯基愈创木酚）。本文报道了肠杆菌Px6-4 FADase及其与底物类似物复合物的晶体结构。我们的分析表明，FADase具有半开口的底部β桶，催化袋位于核心β桶的中间和螺旋底部之间。其结构与酚酸脱羧酶（PAD）超家族成员具有高度相似性。结构分析表明，FADase通过一种“开闭”机制催化反应，该机制涉及酶表面上8×8×15 Å尺寸的口袋。当底物类似物诱导时，活性袋可直接与溶剂接触并允许底物进入。定点诱变表明，E134A突变使酶活性降低60%以上，Y21A和Y27A突变使酶活性完全丧失。结合结构和诱变结果表明，在FADase对阿魏酸的脱羧过程中，Trp25和Tyr27需要进入底物并使底物定向，而Glu134和Asn23参与质子转移。
Microbial ferulic acid decarboxylase (FADase) catalyzes the transformation of ferulic acid to 4-hydroxy-3-methoxystyrene (4-vinylguaiacol) via non-oxidative decarboxylation. Here we report the crystal structures of the Enterobacter sp. Px6-4 FADase and the enzyme in complex with substrate analogues. Our analyses revealed that FADase possessed a half-opened bottom β-barrel with the catalytic pocket located between the middle of the core β-barrel and the helical bottom. Its structure shared a high degree of similarity with members of the phenolic acid decarboxylase (PAD) superfamily. Structural analysis revealed that FADase catalyzed reactions by an “open-closed” mechanism involving a pocket of 8×8×15 Å dimension on the surface of the enzyme. The active pocket could directly contact the solvent and allow the substrate to enter when induced by substrate analogues. Site-directed mutagenesis showed that the E134A mutation decreased the enzyme activity by more than 60%, and Y21A and Y27A mutations abolished the enzyme activity completely. The combined structural and mutagenesis results suggest that during decarboxylation of ferulic acid by FADase, Trp25 and Tyr27 are required for the entering and proper orientation of the substrate while Glu134 and Asn23 participate in proton transfer.
登录
查看更多内容
影响因子：
4.4
作者：
DEGRASSI, G;DELAURETO, PP;BRUSCHI, CV
通讯作者：
BRUSCHI, CV
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
4.4
作者：
HUANG, ZX;DOSTAL, L;ROSAZZA, JPN
通讯作者：
ROSAZZA, JPN
影响因子：
4.4
作者：
Li, Xuemei;Yang, Jinkui;Zhang, Ke-Qin
通讯作者：
Zhang, Ke-Qin
影响因子：
4.8
作者：
Cendron, Laura;Berni, Rodolfo;Zanotti, Giuseppe
通讯作者：
Zanotti, Giuseppe