Lichen Biosynthetic Gene Clusters Part II: Homology Mapping Suggests a Functional Diversity
Lichen Biosynthetic Gene Clusters Part II: Homology Mapping Suggests a Functional Diversity
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DOI：
10.1021/acs.jnatprod.7b00770
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发表时间：
2018-04-01
影响因子：
5.1
通讯作者：
Sorensen, John L.
中科院分区：
文献类型：
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作者：
Bertrand, Robert L.;Abdel-Hameed, Mona;Sorensen, John L.
地衣以其多样的天然产物而闻名，但对地衣天然产物生物合成的遗传程序知之甚少。我们对Cladonia uncialis的基因组进行了测序，并分析了其次级代谢产物生物合成基因簇。通过同源性搜索方法，我们现在可以提出基因产物的特定功能以及在这些基因簇中编码的生物合成途径。该分析显示地衣基因组编码展青霉素和β-烯酮A-C生物合成所需的酶，这些真菌毒素不知道由地衣产生。在几个基因簇中，一些（但不是全部）基因在遗传上与真菌中致力于次级代谢物生物合成的基因相似。这些地衣集群还包含辅助剪裁基因，没有这样的遗传相似性，这表明编码的剪裁酶进行不同的化学转化。我们假设C. uncialis基因簇通过改组祖先真菌簇的组分而进化，以产生新的一系列化学步骤，导致产生迄今未发现的真菌次级代谢产物的衍生物。
Lichens are renowned for their diverse natural products though little is known of the genetic programming dictating lichen natural product biosynthesis. We sequenced the genome of Cladonia uncialis and profiled its secondary metabolite biosynthetic gene clusters. Through a homology searching approach, we can now propose specific functions for gene products as well as the biosynthetic pathways that are encoded in several of these gene clusters. This analysis revealed that the lichen genome encodes the required enzymes for patulin and betaenones A-C biosynthesis, fungal toxins not known to be produced by lichens. Within several gene clusters, some (but not all) genes are genetically similar to genes devoted to secondary metabolite biosynthesis in Fungi. These lichen clusters also contain accessory tailoring genes without such genetic similarity, suggesting that the encoded tailoring enzymes perform distinct chemical transformations. We hypothesize that C. uncialis gene clusters have evolved by shuffling components of ancestral fungal clusters to create new series of chemical steps, leading to the production of hitherto undiscovered derivatives of fungal secondary metabolites.