Identification of protein secretion systems and novel secreted proteins in Rhizobium leguminosarum bv. viciae.
Identification of protein secretion systems and novel secreted proteins in Rhizobium leguminosarum bv. viciae.
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DOI：
10.1186/1471-2164-9-55
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发表时间：
2008-01-29
期刊：
影响因子：
4.4
通讯作者：
Downie, J. Allan
中科院分区：
文献类型：
--
作者：
Krehenbrink, Martin;Downie, J. Allan
细菌分泌的蛋白质在感染真核宿主中起重要作用。根瘤菌感染豆科植物的根部并建立互利共生。一些根瘤菌在侵染过程中分泌的蛋白质可以影响侵染并改变植物防御信号通路。本研究的目的是系统地分析蛋白质分泌在最近测序的菌株豆科根瘤菌bv。viciae 3841.以其他革兰氏阴性菌的蛋白质分泌系统为查询序列进行相似性搜索，结果表明，R。L. BV. viciae 3841具有十个推定的蛋白质分泌系统。它们是一般输出途径（GEP）、双精氨酸移位酶（达特）分泌系统、四个独立的I型系统、一个推定的IV型系统和三个V型自身转运蛋白。产生编码这些中的每一个（除了GEP）的基因中的突变，但是仅观察到影响PrsDE（I型）和达特系统的突变影响培养物上清液中的生长表型和蛋白质谱。培养上清液蛋白的胰蛋白酶消化片段的生物信息学分析和质量指纹鉴定了14种推定的I型底物，其中12种通过PrsDE分泌系统分泌。达特突变体是有缺陷的共生，形成根瘤不能固氮。没有一个R。L. BV. viciae 3841蛋白质分泌系统推测参与蛋白质分泌到细胞外空间（I型、IV型、V型），是建立与豆类共生所必需的。PrsDE（I型）系统被证明是非共生细胞中蛋白分泌的主要途径，并分泌大小和预测功能差异很大的蛋白。这与来自其他细菌的许多I型系统形成对比，所述I型系统通常分泌由基因编码的特异性底物，所述基因通常位于编码分泌系统本身的基因附近。
Proteins secreted by bacteria play an important role in infection of eukaryotic hosts. Rhizobia infect the roots of leguminous plants and establish a mutually beneficial symbiosis. Proteins secreted during the infection process by some rhizobial strains can influence infection and modify the plant defence signalling pathways. The aim of this study was to systematically analyse protein secretion in the recently sequenced strain Rhizobium leguminosarum bv. viciae 3841. Similarity searches using defined protein secretion systems from other Gram-negative bacteria as query sequences revealed that R. l. bv. viciae 3841 has ten putative protein secretion systems. These are the general export pathway (GEP), a twin-arginine translocase (TAT) secretion system, four separate Type I systems, one putative Type IV system and three Type V autotransporters. Mutations in genes encoding each of these (except the GEP) were generated, but only mutations affecting the PrsDE (Type I) and TAT systems were observed to affect the growth phenotype and the profile of proteins in the culture supernatant. Bioinformatic analysis and mass fingerprinting of tryptic fragments of culture supernatant proteins identified 14 putative Type I substrates, 12 of which are secreted via the PrsDE, secretion system. The TAT mutant was defective for the symbiosis, forming nodules incapable of nitrogen fixation. None of the R. l. bv. viciae 3841 protein secretion systems putatively involved in the secretion of proteins to the extracellular space (Type I, Type IV, Type V) is required for establishing the symbiosis with legumes. The PrsDE (Type I) system was shown to be the major route of protein secretion in non-symbiotic cells and to secrete proteins of widely varied size and predicted function. This is in contrast to many Type I systems from other bacteria, which typically secrete specific substrates encoded by genes often localised in close proximity to the genes encoding the secretion system itself.
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影响因子：
3.2
作者：
Ausmees, N;Kobayashi, H;Perret, X
通讯作者：
Perret, X
影响因子：
3.2
作者：
BANERJEE, S;FRAENKEL, DG
通讯作者：
FRAENKEL, DG
影响因子：
3.5
作者：
Bladergroen, MR;Badelt, K;Spaink, HP
通讯作者：
Spaink, HP
影响因子：
11.4
作者：
BAUMANN, U;WU, S;MCKAY, DB
通讯作者：
MCKAY, DB
影响因子：
4.8
作者：
Ajouz, B;Berrier, C;Ghazi, E
通讯作者：
Ghazi, E