Gene Cluster Involved in the Biosynthesis of Griseobactin, a Catechol-Peptide Siderophore of Streptomyces sp ATCC 700974
Gene Cluster Involved in the Biosynthesis of Griseobactin, a Catechol-Peptide Siderophore of Streptomyces sp ATCC 700974
复制标题
DOI：
10.1128/jb.01250-09
复制
发表时间：
2010-01-01
影响因子：
3.2
通讯作者：
Braun, Volkmar
中科院分区：
文献类型：
--
作者：
Patzer, Silke I.;Braun, Volkmar
链霉菌产生的主要铁载体是去铁胺。在这里，我们表明，链霉菌ATCC 700974和几个灰色链霉菌菌株，此外，合成一个迄今未知的铁载体与儿茶酚肽结构，命名为灰杆菌素。生产受到铁的抑制。我们测序了一个26-kb的DNA区域，包括一个铁载体生物合成基因簇，编码类似于DhbABCEFG的蛋白质，这些蛋白质参与2，3-二羟基苯甲酸酯（DHBA）的生物合成，并通过非核糖体肽合成酶将DHBA掺入铁载体。与生物合成基因相邻的是编码用于分泌、摄取和降解铁载体的蛋白质的基因。为了将基因簇与灰杆菌素合成相关联，破坏ATCC 700974中的dhb基因。由此产生的突变体不再合成DHBA和灰杆菌素;通过与dhb基因互补，两者的生产得以恢复。dhb基因或整个灰杆菌素生物合成基因簇在儿茶酚阴性菌株变铅青链霉菌TK 23中的异源表达分别导致DHBA或灰杆菌素的合成和分泌，表明这些基因足以用于DHBA和灰杆菌素的生物合成。灰杆菌素进行了纯化和表征;其结构与在铁限制条件下与铝络合的2，3-二羟基苯甲酰基-天冬酰基-苏氨酸的三聚体酯的环状和在较小程度上的线性形式一致。这是首次在链霉菌中鉴定出DHBA和邻苯二酚铁载体生物合成的基因簇。
The main siderophores produced by streptomycetes are desferrioxamines. Here we show that Streptomyces sp. ATCC 700974 and several Streptomyces griseus strains, in addition, synthesize a hitherto unknown siderophore with a catechol-peptide structure, named griseobactin. The production is repressed by iron. We sequenced a 26-kb DNA region comprising a siderophore biosynthetic gene cluster encoding proteins similar to DhbABCEFG, which are involved in the biosynthesis of 2,3-dihydroxybenzoate (DHBA) and in the incorporation of DHBA into siderophores via a nonribosomal peptide synthetase. Adjacent to the biosynthesis genes are genes that encode proteins for the secretion, uptake, and degradation of siderophores. To correlate the gene cluster with griseobactin synthesis, the dhb genes in ATCC 700974 were disrupted. The resulting mutants no longer synthesized DHBA and griseobactin; production of both was restored by complementation with the dhb genes. Heterologous expression of the dhb genes or of the entire griseobactin biosynthesis gene cluster in the catechol-negative strain Streptomyces lividans TK23 resulted in the synthesis and secretion of DHBA or griseobactin, respectively, suggesting that these genes are sufficient for DHBA and griseobactin biosynthesis. Griseobactin was purified and characterized; its structure is consistent with a cyclic and, to a lesser extent, linear form of the trimeric ester of 2,3-dihydroxybenzoyl-arginyl-threonine complexed with aluminum under iron-limiting conditions. This is the first report identifying the gene cluster for the biosynthesis of DHBA and a catechol siderophore in Streptomyces.