Matthijs Sandra, Baysse Christine, Koedam Nico, Tehrani Kourosh Abbaspour, Verheyden Lieve, Budzikiewicz Herbert, Schäfer Mathias, Hoorelbeke Bart, Meyer Jean-Marie, De Greve Henri, Cornelis Pierre
Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Interuniversity Institute for Biotechnology, Vrije Universiteit Brussel, Building E, Pleinlaan 2, 1050 Brussels, Belgium.
Mol Microbiol. 2004 Apr;52(2):371-84. doi: 10.1111/j.1365-2958.2004.03999.x.
To cope with iron deficiency fluorescent pseudomonads produce pyoverdines which are complex peptidic siderophores that very efficiently scavenge iron. In addition to pyoverdine some species also produce other siderophores. Recently, it was shown that Pseudomonas fluorescens ATCC 17400 produces the siderophore quinolobactin, an 8-hydroxy-4-methoxy-2-quinoline carboxylic acid (Mossialos, D., Meyer, J.M., Budzikiewicz, H., Wolff, U., Koedam, N., Baysse, C., Anjaiah, V., and Cornelis, P. (2000) Appl Environ Microbiol 66: 487-492). The entire quinolobactin biosynthetic, transport and uptake gene cluster, consisting out of two operons comprising 12 open reading frames, was cloned and sequenced. Based on the genes present and physiological complementation assays a biosynthetic pathway for quinolobactin is proposed. Surprisingly, this pathway turned out to combine genes derived from the eukaryotic tryptophan-xanthurenic acid branch of the kynurenine pathway and from the pathway for the biosynthesis of pyridine-2,6-bis(thiocarboxylic acid) from P. stutzeri, PDTC. These results clearly show the involvement of the tryptophan-kynurenine-xanthurenic acid pathway in the synthesis of an authentic quinoline siderophore.
为应对缺铁情况，荧光假单胞菌会产生吡嗪菌素，这是一类复杂的肽类铁载体，能非常有效地 scavenge iron。除了吡嗪菌素，一些菌株还会产生其他铁载体。最近研究表明，荧光假单胞菌ATCC 17400能产生铁载体喹诺菌素，即一种8 - 羟基 - 4 - 甲氧基 - 2 - 喹啉羧酸（Mossialos, D., Meyer, J.M., Budzikiewicz, H., Wolff, U., Koedam, N., Baysse, C., Anjaiah, V., and Cornelis, P. (2000) Appl Environ Microbiol 66: 487 - 492）。整个喹诺菌素生物合成、转运和摄取基因簇，由两个包含12个开放阅读框的操纵子组成，已被克隆并测序。基于所存在的基因和生理互补分析，提出了喹诺菌素的生物合成途径。令人惊讶的是，该途径竟然结合了源自真核生物犬尿氨酸途径中色氨酸 - 黄尿酸分支的基因以及源自施氏假单胞菌吡啶 - 2,6 - 双（硫代羧酸）生物合成途径（PDTC）的基因。这些结果清楚地表明色氨酸 - 犬尿氨酸 - 黄尿酸途径参与了一种真正喹啉铁载体的合成。
