One protein, two enzymes
One protein, two enzymes
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DOI：
10.1074/jbc.274.3.1193
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发表时间：
1999-01-15
影响因子：
4.8
通讯作者：
Abeles, RH
中科院分区：
文献类型：
--
作者：
Dai, Y;Wensink, PC;Abeles, RH
两种酶，命名为E-2和E-2‘，催化蛋氨酸回收途径中ACI还原内酯中间体的不同氧化反应。E-2和E-2‘在大肠杆菌中由同一基因过度表达，具有相同的蛋白质组分。E-2和E-2‘可在阴离子交换柱或疏水柱上分离。由于结合了不同的金属，它们具有不同的催化和层析性能。从两种酶中去除金属后得到的载脂蛋白酶在催化作用下是不活跃的。在脱辅基蛋白中加入Ni2+或Co2+可产生E-2活性。当加入Fe2+时，可获得E-2‘活性。在完整的大肠杆菌中产生E-2和E-2‘取决于相应金属的可用性。这些观察结果表明，金属成分决定了反应的特异性。
Two enzymes, designated, E-2 and E-2', catalyze different oxidation reactions of an aci-reductone intermediate in the methionine salvage pathway. E-2 and E-2', overproduced in Escherichia coli from the same gene, have the same protein component. E-2 and E-2' are separable on an anion exchange column or a hydrophobic column. Their distinct catalytic and chromatographic properties result from binding different metals. The apo enzyme, obtained after metal is removed from either enzyme, is catalytically inactive. Addition of Ni2+ or Co2+ to the apo-protein yields E-2 activity. E-2' activity is obtained when Fe2+ is added. Production in intact E. coli of E-2 and E-2' depends on the availability of the corresponding metals. These observations suggest that the metal component dictates reaction specificity.