Characterization of the Nonconserved hpaB-hrpF Region in the hrp Pathogenicity Island from Xanthomonas campestris pv. vesicatoria
Characterization of the Nonconserved hpaB-hrpF Region in the hrp Pathogenicity Island from Xanthomonas campestris pv. vesicatoria
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DOI：
10.1094/mpmi-20-9-1063
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发表时间：
2007-09-01
影响因子：
3.5
通讯作者：
Bonas, Ulla
中科院分区：
文献类型：
--
作者：
Buettner, Daniela;Noel, Laurent;Bonas, Ulla
革兰氏阴性植物病原菌野油菜黄单胞菌的相互作用泡囊病菌与其寄主植物辣椒和番茄一起，是由一种III型分泌系统(US)介导的，该系统将细菌效应蛋白转移到植物细胞中。T3S系统由染色体上的HRP(超敏反应和致病性)基因簇编码。在这里，我们报告了hpaB-hrpF区的分析，它编码了新的毒力因子HPAE，效应蛋白XopF1，以及两个功能未知的蛋白HPAD和HPAL。启动子和转录分析表明，相应的基因与hrp基因共表达，HPAD、HPAI和xopF1形成一个新的操纵子。体外和体内分析表明，XopF1的有效T3S和易位依赖于全局T3S伴侣HpaB和假定的裂解转糖基酶HpaH，后者特异性地促进了特定效应物的分泌。综上所述，我们的数据表明，野油菜黄单胞菌能够高效地分泌效应器蛋白。水泡症需要几种不同的HPA蛋白共同作用。
The interaction of the gram-negative phytopathogenic bacterium Xanthomonas campestris pv. vesicatoria with its host plants pepper and tomato is mediated by a type III secretion (US) system that translocates bacterial effector proteins into the plant cell. The T3S system is encoded by the chromosomal hrp (hypersensitive response and pathogenicity) gene cluster. Here, we report on the analysis of the hpaB-hrpF region, which encodes the novel virulence factor HpaE, the effector protein XopF1, and two proteins with unknown functions, HpaD and Hpal. Promoter and transcript analyses revealed that the corresponding genes are coexpressed with the hrp genes and that hpaD, hpaI, and xopF1 form a novel operon. In vitro and in vivo assays showed that the efficient T3S and translocation of XopF1 depends on the global T3S chaperone HpaB and the putative lytic transglycosylase HpaH, which specifically contributes to the secretion of a certain set of effectors. Taken together, our data suggest that the efficient secretion of effector proteins in X. campestris pv. vesicatoria requires the contribution of several different Hpa proteins.