Structural insights into the coordination of plastid division by the ARC6-PDV2 complex
Structural insights into the coordination of plastid division by the ARC6-PDV2 complex
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ARC6-PDV2 复合体协调质体分裂的结构见解。
DOI：
10.1038/nplants.2017.11
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发表时间：
2017-03-01
期刊：
影响因子：
18
通讯作者：
Feng, Yue
中科院分区：
文献类型：
--
作者：
Wang, Wenhe;Li, Jinyu;Feng, Yue
叶绿体分裂的二分裂，这是通过同时收缩的FtsZ环的基质侧的内被膜，和ARC 5环的胞质侧的外被膜。这两个环主要通过内膜蛋白ARC 6和外膜蛋白PDV 2在膜间隙中的相互作用而连接和协调。这种协调的基本机制迄今尚不清楚。在这里，我们解决了ARC 6-PDV 2复合物的膜间空间区域的晶体结构。结果表明，PDV 2将其羧基末端插入ARC 6中形成的口袋中，并且这种相互作用进一步诱导两个ARC 6分子的膜间空间区域的二聚化。PDV 2突变体减弱PDV 2诱导的ARC 6二聚化，在植物细胞中显示ARC 6环的异常形态和受损的叶绿体分裂。总之，我们的数据表明，PDV 2诱导的ARC 6二聚化在叶绿体分裂中起着关键作用，并提供了内部和外部质体分裂机制的协调机制的见解。
Chloroplasts divide by binary fission, which is accomplished by the simultaneous constriction of the FtsZ ring on the stromal side of the inner envelope membrane, and the ARC5 ring on the cytosolic side of the outer envelope membrane. The two rings are connected and coordinated mainly by the interaction between the inner envelope membrane protein ARC6 and the outer envelope membrane protein PDV2 in the intermembrane space. The underlying mechanism of this coordination is unclear to date. Here, we solved the crystal structure of the intermembrane space region of the ARC6-PDV2 complex. The results indicated that PDV2 inserts its carboxy terminus into a pocket formed in ARC6, and this interaction further induces the dimerization of the intermembrane space regions of two ARC6 molecules. A pdv2 mutant attenuating PDV2-induced ARC6 dimerization showed abnormal morphology of ARC6 rings and compromised chloroplast division in plant cells. Together, our data reveal that PDV2-induced dimerization of ARC6 plays a critical role in chloroplast division and provide insights into the coordination mechanism of the internal and external plastid division machineries.