Förster-Fromme Karin, Jendrossek Dieter
Institut für Mikrobiologie, Universität Stuttgart, Stuttgart, Germany.
FEMS Microbiol Lett. 2006 Nov;264(2):220-5. doi: 10.1111/j.1574-6968.2006.00454.x.
The catabolism of citronellol and geraniol [acyclic terpene utilization (Atu) pathway] was investigated in Pseudomonas citronellolis. A 13.3-kb genomic DNA fragment was cloned and harboured a putative regulator gene atuR and a gene cluster consisting of eight genes (atuABCDEFGH). Sequence analysis of the atu gene products showed a high degree of amino acid similarity (78-91% identity) to products of a similar gene cluster previously identified in Pseudomonas aeruginosa. Insertion mutagenesis in atuA resulted in inability of the bacteria to utilize acyclic terpenes as a sole source of carbon and energy and confirmed the involvement of atuA in the Atu pathway. Western blot analysis of wild-type and atuA mutant cells of P. citronellolis and P. aeruginosa for biotin-containing proteins enabled the identification of geranyl-CoA carboxylase (GCase), which is the key enzyme of the Atu pathway. GCase subunits were encoded by atuC and atuF. Putative functions for the other Atu proteins in the catabolic pathway of acyclic terpenes are discussed.
在香茅假单胞菌中研究了香茅醇和香叶醇的分解代谢[无环萜烯利用（Atu）途径]。克隆了一个13.3kb的基因组DNA片段，其含有一个假定的调节基因atuR和一个由八个基因（atuABCDEFGH）组成的基因簇。atu基因产物的序列分析表明，其与先前在铜绿假单胞菌中鉴定的类似基因簇的产物具有高度的氨基酸相似性（78-91%的同一性）。atuA中的插入诱变导致细菌无法利用无环萜烯作为唯一的碳源和能源，并证实atuA参与了Atu途径。对香茅假单胞菌和铜绿假单胞菌的野生型和atuA突变体细胞进行含生物素蛋白的蛋白质印迹分析，能够鉴定出香叶酰辅酶A羧化酶（GCase），它是Atu途径的关键酶。GCase亚基由atuC和atuF编码。讨论了其他Atu蛋白在无环萜烯分解代谢途径中的假定功能。
