Chlamydia trachomatis protein CT009 is a structural and functional homolog to the key morphogenesis component RodZ and interacts with division septal plane localized MreB
Chlamydia trachomatis protein CT009 is a structural and functional homolog to the key morphogenesis component RodZ and interacts with division septal plane localized MreB
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DOI：
10.1111/mmi.12855
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发表时间：
2015-02-01
影响因子：
3.6
通讯作者：
Hefty, P. Scott
中科院分区：
文献类型：
--
作者：
Kemege, Kyle E.;Hickey, John M.;Hefty, P. Scott
衣原体的细胞分裂了解甚少，因为缺乏与大多数保守的细菌细胞分裂蛋白的明显同源物，并且存在伸长（杆状）相关蛋白表明可能采用非经典机制。杆状决定蛋白MreB被认为在衣原体细胞分裂中起着独特的作用。在其他生物体中，MreB是需要RodZ才能正常发挥功能的延伸复合体的一部分。最近的一项研究报道，由ORF CT009编码的蛋白质与MreB相互作用，尽管与RodZ的序列相似性较低。本文的研究通过蛋白质结构、诱变和细胞定位分析扩展了这些观察结果。结构分析表明，CT009与RodZ具有高度的结构相似性，揭示了对MreB相互作用至关重要的两个残基的保守取向。在RodZ缺陷型大肠杆菌中，取代消除了CT009提供的MreB蛋白相互作用和部分互补。CT009的细胞定位分析显示衣原体中均匀的膜染色。这与MreB的定位相反，MreB的定位仅限于预测的间隔平面。MreB定位于隔平面为MreB在细胞分裂中的作用提供了直接的实验观察，并支持其在衣原体中作为FtsZ的功能替代的假设。
Cell division in Chlamydiae is poorly understood as apparent homologs to most conserved bacterial cell division proteins are lacking and presence of elongation (rod shape) associated proteins indicate non-canonical mechanisms may be employed. The rod-shape determining protein MreB has been proposed as playing a unique role in chlamydial cell division. In other organisms, MreB is part of an elongation complex that requires RodZ for proper function. A recent study reported that the protein encoded by ORF CT009 interacts with MreB despite low sequence similarity to RodZ. The studies herein expand on those observations through protein structure, mutagenesis and cellular localization analyses. Structural analysis indicated that CT009 shares high level of structural similarity to RodZ, revealing the conserved orientation of two residues critical for MreB interaction. Substitutions eliminated MreB protein interaction and partial complementation provided by CT009 in RodZ deficient Escherichia coli. Cellular localization analysis of CT009 showed uniform membrane staining in Chlamydia. This was in contrast to the localization of MreB, which was restricted to predicted septal planes. MreB localization to septal planes provides direct experimental observation for the role of MreB in cell division and supports the hypothesis that it serves as a functional replacement for FtsZ in Chlamydia.