Expression of the bph genes involved in biphenyl/PCB degradation in Pseudomonas sp. KKS102 induced by the biphenyl degradation intermediate, 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid.
Expression of the bph genes involved in biphenyl/PCB degradation in Pseudomonas sp. KKS102 induced by the biphenyl degradation intermediate, 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid.
复制标题
DOI：
10.1016/s0378-1119(00)00349-8
复制
发表时间：
2000-10
期刊：
影响因子：
3.5
通讯作者：
Y. Ohtsubo;Y. Nagata;K. Kimbara;M. Takagi;A. Ohta
中科院分区：
文献类型：
--
作者：
Y. Ohtsubo;Y. Nagata;K. Kimbara;M. Takagi;A. Ohta
假单胞菌BPH基因参与多氯联苯降解的研究KKS102为bphEGFA1A2A3BCDA4R。在联苯存在的情况下，BPH基因可以诱导表达。为了更全面地了解BPH基因的诱导，对BPH基因表达的诱导物进行了研究。为了鉴定诱导分子，我们构建了四个结构基因的缺失突变体，并分析了bphE基因在每个突变株中的诱导性。在野生型细胞和bphD缺失突变体中，联苯的存在提高了bphE转录本的水平。另一方面，在bphA、bphB和bphC缺失突变体中，联苯的存在并没有提高bphE转录本的水平。这些结果表明，联苯双加氧酶(BPhA)、二氢二醇脱氢酶(BphB)和2，3-二羟基联苯双加氧酶(BPHC)催化的一系列反应是联苯转化为诱导剂所必需的。已知这些反应将联苯转化为2-羟基-6-氧代-6-苯基-2，4-二烯酸(HOPDA)，并发现纯化的HOPDA可诱导BPH基因的表达。这些结果清楚地表明HOPDA是KKS102中BPH基因的诱导者。
The bph genes involved in PCB/biphenyl degradation in Pseudomonas sp. KKS102 are clustered as bphEGFA1A2A3BCDA4R. The bph genes are inducibly expressed in the presence of biphenyl. In order to understand the induction more fully, the inducer of bph gene expression was investigated. To identify the inducer molecule, we constructed four deletion mutants of the structural genes and analyzed the inducibility of the bphE gene in each mutant strain. In the wild-type cell and the bphD deletion mutant, the levels of the bphE transcript were enhanced in the presence of biphenyl. On the other hand, in the bphA, bphB, and bphC deletion mutants, levels of the bphE transcript were not enhanced in the presence of biphenyl. These results demonstrated that the series of reactions catalyzed by biphenyl dioxygenase (BphA), dihydrodiol dehydrogenase (BphB), and 2,3-dihydroxybiphenyl dioxygenase (BphC) are necessary to convert biphenyl to the inducer. It is known that these reactions convert biphenyl to 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid (HOPDA), and it was found that the expression of the bph genes was induced by purified HOPDA. These results clearly indicate that HOPDA is the inducer of the bph genes in KKS102.