Identification of an opd (organophosphate degradation) gene in an Agrobacterium isolate
Identification of an opd (organophosphate degradation) gene in an Agrobacterium isolate
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DOI：
10.1128/aem.68.7.3371-3376.2002
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发表时间：
2002-07-01
影响因子：
4.4
通讯作者：
Oakeshott, JG
中科院分区：
文献类型：
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作者：
Horne, I;Sutherland, TD;Oakeshott, JG
我们分离到一株能水解多种有机磷杀虫剂的菌株，放射性土壤杆菌P230。从A.放射性同位素标记P230并测序。该基因（称为opdA）与opd具有序列相似性，opd是先前显示在黄杆菌属菌株ATCC 27551和缺陷短波单胞菌MG中编码OP水解酶的基因。opdA基因的插入突变产生的菌株缺乏水解OP的能力，这表明这是唯一的基因编码的OP水解酶在A。放射性P230。分别由opd和opdA编码的OPH和OpdA蛋白被过表达并纯化为麦芽糖结合蛋白，并且麦芽糖结合蛋白部分被切割并去除。两种蛋白质都不能水解脂肪族OP马拉硫磷。两种蛋白质对二乙基OP的动力学是相当的。对于二甲基OP，OpdA具有比OPH更高的k（cat）。它还能够水解二甲基有机磷农药敌百虫和倍硫磷，而OPH在可检测的水平上不会水解这些农药。
We isolated a bacterial strain, Agrobacterium radiobacter P230, which can hydrolyze a wide range of organophosphate (OP) insecticides. A gene encoding a protein involved in OP hydrolysis was cloned from A. radiobaeter P230 and sequenced. This gene (called opdA) had sequence similarity to opd, a gene previously shown to encode an OP-hydrolyzing enzyme in Flavobacterium sp. strain ATCC 27551 and Brevundimonas diminuta MG. Insertional mutation of the opdA gene produced a strain lacking the ability to hydrolyze OPs, suggesting that this is the only gene encoding an OP-hydrolyzing enzyme in A. radiobacter P230. The OPH and OpdA proteins, encoded by opd and opdA, respectively, were overexpressed and purified as maltose-binding proteins, and the maltose-binding protein moiety was cleaved and removed. Neither protein was able to hydrolyze the aliphatic OP malathion. The kinetics of the two proteins for diethyl OP's were comparable. For dimethyl OPs, OpdA had a higher k(cat) than OPH. It was also capable of hydrolyzing the dimethyl OPs phosmet and fenthion, which were not hydrolyzed at detectable levels by OPH.