Plasticity and Evolution of Aeruginosin Biosynthesis in Cyanobacteria
Plasticity and Evolution of Aeruginosin Biosynthesis in Cyanobacteria
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DOI：
10.1128/aem.02258-08
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发表时间：
2009-04-01
影响因子：
4.4
通讯作者：
de Marsac, Nicole Tandeau
中科院分区：
文献类型：
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作者：
Ishida, Keishi;Welker, Martin;de Marsac, Nicole Tandeau
Aerobiosins是由水华蓝藻微囊藻属和浮游发藻属的菌株产生的具有高度结构多样性的生物活性寡肽。Aerobiosins的一个标志是四肽中心的不寻常的Choi部分，而其他位置则由单个同源物中的可变部分占据。本文报道了铜绿微囊藻（Microcystis aeruginosa，PCC 7806、NIES-98和NIES-843）的3个AERO合成酶基因簇（AER）。对aer基因簇的分析和比较首次揭示了aerodosin途径生物合成和结构可塑性的分子基础。aer基因簇的主要部分在所有菌株中高度相似，特别是编码前三个非核糖体肽合成酶（NRPS）模块的基因，除了编码第二个腺苷酸化结构域的区域。然而，基因簇在编码定制酶如卤化酶和磺基转移酶的基因上有很大不同，反映了单个菌株产生的嗜氧红蛋白同系物的结构特性。在C-末端NRPS模块中进一步观察到显著的偏差，表明两种不同的释放机制。基因簇的结构与由单个菌株产生的特定的气溶胶蛋白变体一致，其中两种（气溶胶蛋白686 A和686 B）的结构被阐明。微囊藻和浮游发藻的aer基因簇被认为起源于一个共同的祖先，并主要通过水平基因转移和重组事件进化到今天的多样性。
Aeruginosins are bioactive oligopeptides that are produced in high structural diversity by strains of the bloom-forming cyanobacterial genera Microcystis and Planktothrix. A hallmark of aeruginosins is the unusual Choi moiety central to the tetrapeptides, while other positions are occupied by variable moieties in individual congeners. Here we report on three aeruginosin synthetase gene clusters (aer) of Microcystis aeruginosa (strains PCC 7806, NIES-98, and NIES-843). The analysis and comparison the aer gene clusters provide the first insight into the molecular basis of biosynthetic and structural plasticity in aeruginosin pathways. Major parts of the aer gene clusters are highly similar in all strains, particularly the genes coding for the first three nonribosomal peptide synthetase (NRPS) modules except for the region coding for the second adenylation domain. However, the gene clusters differ largely in genes coding for tailoring enzymes such as halogenases and sulfotransferases, reflecting structural peculiarities in aeruginosin congeners produced by the individual strains. Significant deviations were further observed in the C-terminal NRPS modules, suggesting two distinct release mechanisms. The architecture of the gene clusters is in agreement with the particular aeruginosin variants that are produced by individual strains, the structures of two of which (aeruginosins 686 A and 686 B) were elucidated. The aer gene clusters of Microcystis and Planktothrix are proposed to originate from a common ancestor and to have evolved to their present-day diversity largely through horizontal gene transfer and recombination events.