A novel stabilization mechanism for the type VI secretion system sheath.
A novel stabilization mechanism for the type VI secretion system sheath.
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DOI：
10.1073/pnas.2008500118
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发表时间：
2021-02-16
影响因子：
11.1
通讯作者：
Filloux A
中科院分区：
文献类型：
--
作者：
Bernal P;Furniss RCD;Fecht S;Leung RCY;Spiga L;Mavridou DAI;Filloux A
T6 SS是一个微小的鱼叉，细菌用它将毒素输送到邻近的细胞中。虽然其复杂的组装过程已被广泛研究，但仍不清楚关键TssA蛋白的两种形式（长和短）如何影响T6 SS功能。TssA促进基板的形成，编排鞘的延伸，并在其长的形式，与合作伙伴的蛋白相互作用，锚延伸鞘在相反的一侧的细胞长达10分钟。在这里，我们证明了短TssA蛋白协助鞘稳定与尚未描述的类T6 SS蛋白积累在基板。这些T6 SS在几秒钟内就能开火;因此，这一发现为研究携带T6 SS的细菌的不同战斗策略提供了深入的了解。VI型分泌系统（T6 SS）是一种主要参与细菌间竞争的噬菌体衍生的收缩性纳米机器。其关键成分TssA对于T6 SS鞘结构的组装是不可或缺的，其收缩将效应蛋白的有效载荷推进到邻近细胞中。尽管它们的关键功能，TssA蛋白表现出意想不到的多样性，并存在于两种主要形式，短形式（TssAS）和长形式（TssAL）。虽然TssAL蛋白与称为TagA的伴侣相互作用以锚延伸鞘的远端，但含有TssAS的T6 SS的稳定机制仍然未知。在这里，我们发现了一类与短TssA蛋白相互作用的结构成分，并通过稳定来自基板的聚合鞘来促进T6 SS组装。我们证明，这些组件的存在是很重要的充分鞘管延伸和最佳的发射。此外，我们表明，配对的每种形式的TssA与不同类别的鞘稳定蛋白的结果在T6 SS装置，要么驻留在细胞中一段时间或火灾后立即鞘延伸。我们认为，这种多样性的发射动力学可能有助于专业化的T6 SS，以适应细菌的生活方式在不同的环境小生境。
The T6SS is a microscopic harpoon that bacteria use to deliver toxins into neighboring cells. While its complex assembly process has been extensively studied, it remains unclear how the two forms (long and short) of the pivotal TssA protein affect T6SS function. TssA promotes baseplate formation, orchestrates sheath extension and, in its long form, interacts with a partner protein to anchor the extending sheath at the opposing side of the cell for up to 10 min. Here we demonstrate that short TssA proteins assist sheath stabilization by associating with a yet undescribed class of T6SS proteins that accumulate at the baseplate. These T6SSs fire in seconds; therefore, this discovery provides insight into the mechanism underpinning the different fighting strategies observed across T6SS-carrying bacteria. The type VI secretion system (T6SS) is a phage-derived contractile nanomachine primarily involved in interbacterial competition. Its pivotal component, TssA, is indispensable for the assembly of the T6SS sheath structure, the contraction of which propels a payload of effector proteins into neighboring cells. Despite their key function, TssA proteins exhibit unexpected diversity and exist in two major forms, a short form (TssAS) and a long form (TssAL). While TssAL proteins interact with a partner, called TagA, to anchor the distal end of the extended sheath, the mechanism for the stabilization of TssAS-containing T6SSs remains unknown. Here we discover a class of structural components that interact with short TssA proteins and contribute to T6SS assembly by stabilizing the polymerizing sheath from the baseplate. We demonstrate that the presence of these components is important for full sheath extension and optimal firing. Moreover, we show that the pairing of each form of TssA with a different class of sheath stabilization proteins results in T6SS apparatuses that either reside in the cell for some time or fire immediately after sheath extension. We propose that this diversity in firing dynamics could contribute to the specialization of the T6SS to suit bacterial lifestyles in diverse environmental niches.
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影响因子：
7.7
作者：
Cooper RM;Tsimring L;Hasty J
通讯作者：
Hasty J
DOI：
10.1016/j.str.2017.12.005
发表时间：
2018-02-06
期刊：
Structure (London, England : 1993)
影响因子：
--
作者：
Salih O;He S;Planamente S;Stach L;MacDonald JT;Manoli E;Scheres SHW;Filloux A;Freemont PS
通讯作者：
Freemont PS
影响因子：
6.7
作者：
Felisberto-Rodrigues C;Durand E;Aschtgen MS;Blangy S;Ortiz-Lombardia M;Douzi B;Cambillau C;Cascales E
通讯作者：
Cascales E
影响因子：
4.5
作者：
Brunet YR;Zoued A;Boyer F;Douzi B;Cascales E
通讯作者：
Cascales E
DOI：
10.15252/embj.201694024
发表时间：
2016-08-01
期刊：
The EMBO journal
影响因子：
--
作者：
Planamente S;Salih O;Manoli E;Albesa-Jové D;Freemont PS;Filloux A
通讯作者：
Filloux A