Identification of a biosynthesis gene cluster for flocculosin a cellobiose lipid produced by the biocontrol agent Pseudozyma flocculosa
Identification of a biosynthesis gene cluster for flocculosin a cellobiose lipid produced by the biocontrol agent Pseudozyma flocculosa
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DOI：
10.1111/j.1365-2958.2010.07533.x
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发表时间：
2011-03-01
影响因子：
3.6
通讯作者：
Belanger, Richard R.
中科院分区：
文献类型：
--
作者：
Teichmann, Beate;Labbe, Caroline;Belanger, Richard R.
P>絮凝素是由生物防治真菌假酵素产生的一种抗真菌糖脂。它由纤维素二糖，o -糖苷连接到3,15,16-三羟基铝酸。糖部分与2-羟基辛酸酰化，并在两个位置乙酰化。在这里，我们描述了一个由11个基因组成的基因簇，这些基因是絮凝素生物合成所必需的。我们将该簇与植物病原真菌黑穗病菌（Ustilago maydis）产生的高度相似的糖脂ustilagic acid （UA）的生物合成基因簇进行了比较。与U. maydis簇相反，絮凝素生物合成簇含有一个额外的编码乙酰转移酶的基因，并且缺乏与UA羟基化所需的α -羟化酶Ahd1同源的基因。通过对相应突变体的互补，研究了3个酰基/乙酰基转移酶基因（Fat1、Fat2和Fat3）及其附加乙酰基转移酶的功能。虽然絮状假体中的Fat1和Fat3与Uat1同源，但Fat2与Uat2具有64%的同源性，Uat2是一种参与UA生物合成但功能未知的蛋白质。通过遗传和质谱分析，我们发现Uat2和Fat2对于相应糖脂的乙酰化是必需的。这些结果为研究絮凝草的生物防治特性和提高其活性提供了独特的见解。
P>Flocculosin is an antifungal glycolipid produced by the biocontrol fungus Pseudozyma flocculosa. It consists of cellobiose, O-glycosidically linked to 3,15,16-trihydroxypalmitic acid. The sugar moiety is acylated with 2-hydroxy-octanoic acid and acetylated at two positions. Here we describe a gene cluster comprising 11 genes that are necessary for the biosynthesis of flocculosin. We compared the cluster with the biosynthesis gene cluster for the highly similar glycolipid ustilagic acid (UA) produced by the phytopathogenic fungus Ustilago maydis. In contrast to the cluster of U. maydis, the flocculosin biosynthesis cluster contains an additional gene encoding an acetyl-transferase and is lacking a gene homologous to the alpha-hydroxylase Ahd1 necessary for UA hydroxylation. The functions of three acyl/acetyl-transferase genes (Fat1, Fat2 and Fat3) including the additional acetyl-transferase were studied by complementing the corresponding U. maydis mutants. While P. flocculosa Fat1 and Fat3 are homologous to Uat1 in U. maydis, Fat2 shares 64% identity to Uat2, a protein involved in UA biosynthesis but with so far unknown function. By genetic and mass spectrometric analysis, we show that Uat2 and Fat2 are necessary for acetylation of the corresponding glycolipid. These results bring unique insights into the biocontrol properties of P. flocculosa and opportunities for enhancing its activity.