Genetic and transcriptional analysis of the siderophore malleobactin biosynthesis and transport genes in the human pathogen Burkholderia pseudomallei K96243
Genetic and transcriptional analysis of the siderophore malleobactin biosynthesis and transport genes in the human pathogen Burkholderia pseudomallei K96243
复制标题
DOI：
10.1128/jb.188.4.1551-1566.2006
复制
发表时间：
2006-02-01
影响因子：
3.2
通讯作者：
Crosa, JH
中科院分区：
文献类型：
--
作者：
Alice, AF;López, CS;Crosa, JH
类鼻疽伯克霍尔德菌是一种革兰氏阴性兼性胞内病原体，可引起类鼻疽病，这是一种人类和动物的侵袭性疾病。为了解决这种细菌对铁限制条件的反应，我们首先通过微阵列对从铁限制和富铁条件下生长的细菌中提取的RNA进行了全局转录分析。我们的研究集中在那些开放阅读框架（ORF）诱导下的铁限制，编码预测的蛋白质，可能参与铁载体malleobactin的生物合成和摄取。我们纯化了这种铁载体，并确定它由至少三种不同分子量的化合物组成。我们证明了ORF BPSL 1776和BPSL 1774，分别命名为mbaA和mbaF，参与了malleobactin的生物合成，而BPSL 1775，命名为fmtA，参与了它的运输。这些基因与另外两个ORF（mbaJ和mbaI）在一个操纵子中，其转录受MbaS控制，MbaS是一种属于细胞质外功能σ因子的蛋白质。有趣的是，mba4，fmtA和mbaS基因的转录不受铁载体malleobactin的可用性控制。
Burkholderia pseudomallei is a gram-negative facultative intracellular pathogen that causes melioidosis, an invasive disease of humans and animals. To address the response of this bacterium to iron-limiting conditions, we first performed a global transcriptional analysis of RNA extracted from bacteria grown under iron-limiting and iron-rich conditions by microarrays. We focused our study on those open reading frames (ORFs) induced under iron limitation, which encoded predicted proteins that could be involved in the biosynthesis and uptake of the siderophore malleobactin. We purified this siderophore and determined that it consisted of at least three compounds with different molecular weights. We demonstrated that ORFs BPSL1776 and BPSL1774, designated mbaA and mbaF, respectively, are involved in the biosynthesis of malleobactin, while BPSL1775, named fmtA, is involved in its transport. These genes are in an operon with two other ORFs (mbaJ and mbaI) whose transcription is under the control of MbaS, a protein that belongs to the extracytoplasmic function sigma factors. Interestingly, the transcription of the mba4, fmtA, and mbaS genes is not controlled by the availability of the siderophore malleobactin.