Identification of a novel type III secretion-associated outer membrane-bound protein from Xanthomonas campestris pv. campestris.
Identification of a novel type III secretion-associated outer membrane-bound protein from Xanthomonas campestris pv. campestris.
复制标题
野油菜黄单胞菌中一种新型 III 型分泌相关外膜结合蛋白的鉴定
DOI：
10.1038/srep42724
复制
发表时间：
2017-02-15
影响因子：
4.6
通讯作者：
Tang JL
中科院分区：
文献类型：
--
作者：
Li L;Li RF;Ming ZH;Lu GT;Tang JL
许多细菌病原体利用 III 型分泌系统 (T3SS) 将效应蛋白易位到真核细胞中以克服宿主防御。迄今为止，我们对 T3SS 分子结构的大部分了解都来自对动物病原体的研究。在植物病原体中，9种Hrc蛋白被认为是T3SS的结构成分，其中HrcC和HrcJ分别形成T3SS的外环和内环。在这里，我们证明了野油菜黄单胞菌 pv. 的一种新型外膜结合蛋白（HpaM）。 Campestris 对于 III 型分泌至关重要，并且在植物病原黄单胞菌属中在结构和功能上是保守的。我们发现 HpaM 的 C 末端延伸到周质中，与 HrcJ 发生物理相互作用，而 HpaM 的中部则与 HrcC 发生物理相互作用。很明显，外环和内环构成了动物病原体中T3SS装置的主要基体。因此，我们推测HpaM可能作为T3SS的结构部件，或者起到辅助组装或影响T3SS装置稳定性的作用。 HpaM 是黄单胞菌属中一种高度普遍且特异的蛋白质，表明黄单胞菌属的 T3SS 在某些方面与其他病原体不同。
Many bacterial pathogens employ the type III secretion system (T3SS) to translocate effector proteins into eukaryotic cells to overcome host defenses. To date, most of our knowledge about the T3SS molecular architecture comes from the studies on animal pathogens. In plant pathogens, nine Hrc proteins are believed to be structural components of the T3SS, of which HrcC and HrcJ form the outer and inner rings of the T3SS, respectively. Here, we demonstrated that a novel outer membrane-bound protein (HpaM) of Xanthomonas campestris pv. campestris is critical for the type III secretion and is structurally and functionally conserved in phytopathogenic Xanthomonas spp. We showed that the C-terminus of HpaM extends into the periplasm to interact physically with HrcJ and the middle part of HpaM interacts physically with HrcC. It is clear that the outer and inner rings compose the main basal body of the T3SS apparatus in animal pathogens. Therefore, we presume that HpaM may act as a T3SS structural component, or play a role in assisting assembling or affecting the stability of the T3SS apparatus. HpaM is a highly prevalent and specific protein in Xanthomonas spp., suggesting that the T3SS of Xanthomonas is distinctive in some aspects from other pathogens.