Scaffolding Protein GspB/OutB Facilitates Assembly of the Dickeya dadantii Type 2 Secretion System by Anchoring the Outer Membrane Secretin Pore to the Inner Membrane and to the Peptidoglycan Cell Wall.
Scaffolding Protein GspB/OutB Facilitates Assembly of the Dickeya dadantii Type 2 Secretion System by Anchoring the Outer Membrane Secretin Pore to the Inner Membrane and to the Peptidoglycan Cell Wall.
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DOI：
10.1128/mbio.00253-22
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发表时间：
2022-06-28
期刊：
影响因子：
6.4
通讯作者：
Shevchik, Vladimir E.
中科院分区：
文献类型：
--
作者：
Zhang, Shiheng;Gu, Shuang;Rycroft, Piers;Ruaudel, Florence;Delolme, Frederic;Robert, Xavier;Ballut, Lionel;Pickersgill, Richard W.;Shevchik, Vladimir E.
关键词：
植物病原变形杆菌Dickeya dadantii通过2型分泌系统（T2 SS）分泌一系列植物细胞壁降解酶和其他毒力因子。T2 SS广泛存在于重要的植物、动物和人类细菌病原体中。这种多蛋白复合物跨越双膜细胞包膜，并通过由促胰液素GspD的15个亚基形成的大的外膜孔分泌完全折叠的蛋白质。分泌素也存在于3型分泌系统和4型皮利中。通常，称为先导素的专门脂蛋白帮助分泌素靶向和组装到外膜中。在这里，我们表明，在D。dadantii，pilotin与支架蛋白GspB协同作用。gspB的缺失深刻地影响分泌素组装、果胶酶分泌和毒力。结构研究表明，GspB具有一个保守的周质同源区结构域，直接与N-末端分泌素结构域相互作用。位点特异性光交联解开体内GspB-GspD复合物的分子细节。我们发现，GspB促进外膜靶向和分泌素孔的组装，并将它们锚定到内膜，而GspB的C-末端延伸为肽聚糖细胞壁中的分泌素通道提供了支架。系统发育分析表明，在其他细菌中，GspB同源物的长度和结构域组成不同，并与同源ATP酶GspA或pilotin GspS协同作用。
The phytopathogenic proteobacterium Dickeya dadantii secretes an array of plant cell wall-degrading enzymes and other virulence factors via the type 2 secretion system (T2SS). T2SSs are widespread among important plant, animal, and human bacterial pathogens. This multiprotein complex spans the double membrane cell envelope and secretes fully folded proteins through a large outer membrane pore formed by 15 subunits of the secretin GspD. Secretins are also found in the type 3 secretion system and the type 4 pili. Usually, specialized lipoproteins termed pilotins assist the targeting and assembly of secretins into the outer membrane. Here, we show that in D. dadantii, the pilotin acts in concert with the scaffolding protein GspB. Deletion of gspB profoundly impacts secretin assembly, pectinase secretion, and virulence. Structural studies reveal that GspB possesses a conserved periplasmic homology region domain that interacts directly with the N-terminal secretin domain. Site-specific photo-cross-linking unravels molecular details of the GspB-GspD complex in vivo. We show that GspB facilitates outer membrane targeting and assembly of the secretin pores and anchors them to the inner membrane while the C-terminal extension of GspB provides a scaffold for the secretin channel in the peptidoglycan cell wall. Phylogenetic analysis shows that in other bacteria, GspB homologs vary in length and domain composition and act in concert with either a cognate ATPase GspA or the pilotin GspS.
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DOI：
10.1126/science.aad2001
发表时间：
2016-03-11
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Chang YW;Rettberg LA;Treuner-Lange A;Iwasa J;Søgaard-Andersen L;Jensen GJ
通讯作者：
Jensen GJ
影响因子：
6.4
作者：
Douzi B;Trinh NTT;Michel-Souzy S;Desmyter A;Ball G;Barbier P;Kosta A;Durand E;Forest KT;Cambillau C;Roussel A;Voulhoux R
通讯作者：
Voulhoux R
影响因子：
3.6
作者：
Collin, Severine;Guilvout, Ingrid;Pugsley, Anthony P.
通讯作者：
Pugsley, Anthony P.
影响因子：
2.7
作者：
BARTELS, C;XIA, TH;WUTHRICH, K
通讯作者：
WUTHRICH, K
影响因子：
5.6
作者：
Bouley, J;Condemine, G;Shevchik, VE
通讯作者：
Shevchik, VE