The SpoIIQ-SpoIIIAH complex of Clostridium difficile controls forespore engulfment and late stages of gene expression and spore morphogenesis.
The SpoIIQ-SpoIIIAH complex of Clostridium difficile controls forespore engulfment and late stages of gene expression and spore morphogenesis.
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DOI：
10.1111/mmi.13311
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发表时间：
2016-04
影响因子：
3.6
通讯作者：
Henriques AO
中科院分区：
文献类型：
--
作者：
Serrano M;Crawshaw AD;Dembek M;Monteiro JM;Pereira FC;Pinho MG;Fairweather NF;Salgado PS;Henriques AO
前孢子被母细胞吞噬是内孢子形成的普遍特征。在枯草芽孢杆菌中，前孢子蛋白SpoIIQ和母细胞蛋白SpoIIIAH形成一个通道，这是孢子形成所必需的，通过该通道培育发育中的孢子。这两种蛋白质也形成了一个吞噬的备份系统。不像在B。在枯草芽孢杆菌中，艰难梭菌的SpoIIQ具有完整的LytM锌结合基序。我们发现C.艰难梭菌导致异常吞噬，且通过单个氨基酸取代（H120 S）破坏SpoIIQ LytM结构域以不同方式损害吞噬。SpoIIQ和SpoIIQH 120 S在整个吞噬过程中与SpoIIIAH相互作用。SpoIIQ，而不是SpoIIQH 120 S，结合Zn 2+，金属的缺乏改变了体外SpoIIQ-SpoIIIAH复合物。可能，SpoIIQH 120 S支持某些细胞的正常吞噬，但不是吞噬完成后所需的复合物的第二功能。我们发现，spoIIQ或spoIIIAH突变体的细胞完全吞噬后，前孢子和母细胞特异性基因表达受损，表明通道样功能。吞噬和通道样功能可能是SpoIIQ-SpoIIIAH的祖先功能，而通过B中冗余机制的出现减轻了对吞噬的需求。枯草杆菌和相关生物。
Engulfment of the forespore by the mother cell is a universal feature of endosporulation. In Bacillus subtilis, the forespore protein SpoIIQ and the mother cell protein SpoIIIAH form a channel, essential for endosporulation, through which the developing spore is nurtured. The two proteins also form a backup system for engulfment. Unlike in B. subtilis, SpoIIQ of Clostridium difficile has intact LytM zinc‐binding motifs. We show that spoIIQ or spoIIIAH deletion mutants of C. difficile result in anomalous engulfment, and that disruption of the SpoIIQ LytM domain via a single amino acid substitution (H120S) impairs engulfment differently. SpoIIQ and SpoIIQH120S interact with SpoIIIAH throughout engulfment. SpoIIQ, but not SpoIIQH120S, binds Zn2+, and metal absence alters the SpoIIQ‐SpoIIIAH complex in vitro. Possibly, SpoIIQH120S supports normal engulfment in some cells but not a second function of the complex, required following engulfment completion. We show that cells of the spoIIQ or spoIIIAH mutants that complete engulfment are impaired in post‐engulfment, forespore and mother cell‐specific gene expression, suggesting a channel‐like function. Both engulfment and a channel‐like function may be ancestral functions of SpoIIQ‐SpoIIIAH while the requirement for engulfment was alleviated through the emergence of redundant mechanisms in B. subtilis and related organisms.