A novel outer membrane β-1,6-glucanase is deployed in the predation of fungi by myxobacteria
A novel outer membrane β-1,6-glucanase is deployed in the predation of fungi by myxobacteria
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一种新型外膜β-1,6-葡聚糖酶被部署在粘细菌捕食真菌中
DOI：
10.1038/s41396-019-0424-x
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发表时间：
2019-09-01
期刊：
影响因子：
11
通讯作者：
Zhang, Zhengguang
中科院分区：
文献类型：
--
作者：
Li, Zhoukun;Ye, Xianfeng;Zhang, Zhengguang
粘细菌对细菌的捕食作用已经研究了几十年。然而，它们对真菌的捕食却很少受到关注。在这里，我们表明，一种新的外膜β-1，6-葡聚糖酶GluM珊瑚球菌属菌株EGB是必不可少的初始传感和有效分解的真菌捕食过程中。GluM属于一个未研究的外膜β桶蛋白家族，其比活性高达24，000 U/mg，其同系物广泛存在于粘细菌中。GluM能够有效地消化真菌细胞壁，抑制稻瘟病菌对水稻的侵染。与gluM的遗传互补恢复了粘球菌CL 1001的真菌捕食能力，这是被破坏的gluM同源桨。不能捕食具有缺乏β-1，6-葡聚糖的细胞壁的真菌表明β-1，6-葡聚糖是GluM的靶向。我们的研究结果表明，GluM赋予粘细菌以真菌为食的能力，并为理解捕食者-猎物相互作用提供了新的见解。考虑到GluM的攻击模式，我们认为β-1，6-葡聚糖是开发新型广谱抗真菌剂的一个有前途的目标。
Myxobacterial predation on bacteria has been investigated for several decades. However, their predation on fungi has received less attention. Here, we show that a novel outer membrane beta-1,6-glucanase GluM from Corallococcus sp. strain EGB is essential for initial sensing and efficient decomposition of fungi during predation. GluM belongs to an unstudied family of outer membrane beta-barrel proteins with potent specific activity up to 24,000 U/mg, whose homologs extensively exist in myxobacteria. GluM was able to digest fungal cell walls efficiently and restrict Magnaporthe oryzae infection of rice plants. Genetic complementation with gluM restored the fungal predation ability of Myxococcus xanthus CL1001, which was abolished by the disruption of gluM homolog oar. The inability to prey on fungi with cell walls that lack beta-1,6-glucans indicates that beta-1,6-glucans are targeted by GluM. Our results demonstrate that GluM confers myxobacteria with the ability to feed on fungi, and provide new insights for understanding predator-prey interactions. Considering the attack mode of GluM, we suggest that beta-1,6-glucan is a promising target for the development of novel broad-spectrum antifungal agents.