Schuler Luc, Ní Chadhain Sinéad M, Jouanneau Yves, Meyer Christine, Zylstra Gerben J, Hols Pascal, Agathos Spiros N
Unité de Génie Biologique, Institut des Sciences de la Vie, Université Catholique de Louvain, Place Croix du Sud, 2/19, B-1348 Louvain-la-Neuve, Belgium.
Appl Environ Microbiol. 2008 Feb;74(4):1050-7. doi: 10.1128/AEM.01627-07. Epub 2007 Dec 21.
In this study, the genes involved in the initial attack on fluorene by Sphingomonas sp. strain LB126 were investigated. The alpha and beta subunits of a dioxygenase complex (FlnA1-FlnA2), showing 63 and 51% sequence identity, respectively, to the subunits of an angular dioxygenase from the gram-positive dibenzofuran degrader Terrabacter sp. strain DBF63, were identified. When overexpressed in Escherichia coli, FlnA1-FlnA2 was responsible for the angular oxidation of fluorene, 9-hydroxyfluorene, 9-fluorenone, dibenzofuran, and dibenzo-p-dioxin. Moreover, FlnA1-FlnA2 was able to oxidize polycyclic aromatic hydrocarbons and heteroaromatics, some of which were not oxidized by the dioxygenase from Terrabacter sp. strain DBF63. The quantification of resulting oxidation products showed that fluorene and phenanthrene were the preferred substrates of FlnA1-FlnA2.
在本研究中，对鞘氨醇单胞菌属菌株LB126最初攻击芴所涉及的基因进行了研究。一种双加氧酶复合体（FlnA1 - FlnA2）的α和β亚基被鉴定出来，它们与革兰氏阳性二苯并呋喃降解菌地杆菌属菌株DBF63的一种角双加氧酶的亚基分别具有63%和51%的序列同一性。当在大肠杆菌中过表达时，FlnA1 - FlnA2负责芴、9 - 羟基芴、9 - 芴酮、二苯并呋喃和二苯并 - p - 二恶英的角氧化。此外，FlnA1 - FlnA2能够氧化多环芳烃和杂芳烃，其中一些不能被地杆菌属菌株DBF63的双加氧酶氧化。对所得氧化产物的定量分析表明，芴和菲是FlnA1 - FlnA2的首选底物。
