A Cytoplasmic Protein Ssl3829 Is Important for NDH-1 Hydrophilic Arm Assembly in Synechocystis sp Strain PCC 6803
A Cytoplasmic Protein Ssl3829 Is Important for NDH-1 Hydrophilic Arm Assembly in Synechocystis sp Strain PCC 6803
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细胞质蛋白 Ssl3829 对于集胞藻中 NDH-1 亲水臂组装很重要。
DOI：
10.1104/pp.15.01796
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发表时间：
2016-06-01
期刊：
影响因子：
7.4
通讯作者：
Ma, Weimin
中科院分区：
文献类型：
--
作者：
Wang, Xiaozhuo;Gao, Fudan;Ma, Weimin
尽管在澄清蓝藻中多个NDH-1复合物的亚基组成和功能方面取得了重大进展，但组装因子及其在组装这些NDH-1复合物中的作用仍然难以捉摸。从转座子标记文库转化的集胞藻菌株PCC 6803中分离出两个对光生长敏感且光系统I周围NDH-1依赖的循环电子传递受损的突变体。这两个突变体都在编码未知蛋白的ssl 3829基因中标记，该蛋白与拟南芥（Arabidopsis thaliana）叶绿素减少7具有显著的相似性。ssl 3829产物定位于细胞质中，并与约300 kD的NDH-1亲水臂组装中间体（NAI）（NAI 300）和NdhI成熟因子Slr 1097缔合。Ssl 3829缺失后，NAI 300复合物在凝胶上不再可见，从而阻碍了NDH-1亲水臂的组装。Ssl 3829的缺失也消除了Slr 1097，从而减少了胞质中成熟NdhI的量，这抑制了NDH-1亲水臂的动态组装过程，因为成熟NdhI是稳定所有功能NAI所必需的。因此，Ssl 3829通过在细胞质中积累NAI 300复合物和Slr 1097蛋白在NDH-1亲水臂的组装中起重要作用。
Despite significant progress in clarifying the subunit compositions and functions of the multiple NDH-1 complexes in cyanobacteria, the assembly factors and their roles in assembling these NDH-1 complexes remain elusive. Two mutants sensitive to high light for growth and impaired in NDH-1-dependent cyclic electron transport around photosystem I were isolated from Synechocystis sp. strain PCC 6803 transformed with a transposon-tagged library. Both mutants were tagged in the ssl3829 gene encoding an unknown protein, which shares significant similarity with Arabidopsis (Arabidopsis thaliana) CHLORORESPIRATORY REDUCTION7. The ssl3829 product was localized in the cytoplasm and associates with an NDH-1 hydrophilic arm assembly intermediate (NAI) of about 300 kD (NAI300) and an NdhI maturation factor, Slr1097. Upon deletion of Ssl3829, the NAI300 complex was no longer visible on gels, thereby impeding the assembly of the NDH-1 hydrophilic arm. The deletion also abolished Slr1097 and consequently reduced the amount of mature NdhI in the cytoplasm, which repressed the dynamic assembly process of the NDH-1 hydrophilic arm because mature NdhI was essential to stabilize all functional NAIs. Therefore, Ssl3829 plays an important role in the assembly of the NDH-1 hydrophilic arm by accumulating the NAI300 complex and Slr1097 protein in the cytoplasm.