Institut für Mikrobiologie, Universität Stuttgart, Germany.
J Basic Microbiol. 2010 Apr;50(2):119-24. doi: 10.1002/jobm.200900178.
Growth of Pseudomonas aeruginosa on acyclic terpene alcohols such as geraniol depends on the presence of the atuRABCDEFGH gene cluster and a functional acyclic terpene utilisation (Atu) pathway. The proteins encoded by the atu gene cluster are necessary but not sufficient for growth on acyclic terpenes. Comparative 2-dimensional polyacrylamide gel electrophoresis of soluble P. aeruginosa proteins revealed the presence of an additional spot (besides Atu proteins) that is specifically expressed in geraniol cells but is absent in isovalerate-grown cells. The spot was identified as PA1982 gene product a pyrroloquinoline quinone (PQQ) dependent ethanol oxidoreductase (QEDH). Inactivation of PA1982 by insertion mutagenesis resulted in inability of the mutant to utilise ethanol and in reduced growth on geraniol. Growth on ethanol was restored by transferring an intact copy of the PA1982 gene into the mutant. The PA1982 gene product was purified from recombinant Escherichia coli and revealed PQQ-dependent oxidoreductase activity with a variety of substrates including acyclic terpene derivates at comparable V(max)-values. Our results show that QEDH participates in oxidation of acyclic terpene derivates in addition to the well-known function in ethanol metabolism.
铜绿假单胞菌在无环萜醇如香叶醇上的生长依赖于 atuRABCDEFGH 基因簇的存在和功能性无环萜醇利用（Atu）途径。atu 基因簇编码的蛋白质对于在无环萜烯上的生长是必要的，但不是充分的。对可溶性铜绿假单胞菌蛋白的比较 2 维聚丙烯酰胺凝胶电泳显示，除了 Atu 蛋白外，还存在一个额外的斑点，该斑点仅在香叶醇细胞中特异性表达，而在异戊酸盐生长的细胞中不存在。该斑点被鉴定为 PA1982 基因产物吡咯喹啉醌（PQQ）依赖性乙醇氧化还原酶（QEDH）。通过插入诱变使 PA1982 失活导致突变体无法利用乙醇，并且在香叶醇上的生长减少。通过将完整的 PA1982 基因转移到突变体中，恢复了突变体在乙醇上的生长。从重组大肠杆菌中纯化了 PA1982 基因产物，并显示出 PQQ 依赖性氧化还原酶活性，具有各种底物，包括无环萜烯衍生物，在可比的 V（max）值下。我们的结果表明，QEDH 除了在乙醇代谢中的已知功能外，还参与了无环萜烯衍生物的氧化。
