CHLORORESPIRATORY REDUCTION 9 is a Novel Factor Required for Formation of Subcomplex A of the Chloroplast NADH Dehydrogenase-Like Complex.
CHLORORESPIRATORY REDUCTION 9 is a Novel Factor Required for Formation of Subcomplex A of the Chloroplast NADH Dehydrogenase-Like Complex.
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DOI：
10.1093/pcp/pcw130
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发表时间：
2016-10
影响因子：
4.9
通讯作者：
Hiroshi Yamamoto;Xiangyuan Fan;K. Sugimoto;Y. Fukao;Lianwei Peng;T. Shikanai
中科院分区：
文献类型：
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作者：
Hiroshi Yamamoto;Xiangyuan Fan;K. Sugimoto;Y. Fukao;Lianwei Peng;T. Shikanai
在维管植物中，叶绿体 NADH 脱氢酶样 (NDH) 复合物是呼吸性 NADH：醌氧化还原酶（复合物 I）的同源物，在类囊体膜中 PSI 周围的循环电子传输中，使用铁氧还蛋白作为电子供体介导质体醌还原。在被子植物中，叶绿体NDH由五个亚复合物组成，并与PSI形成超级复合物。最近报道了基质突出的子复合物 A 的模块化组装，它对应于复合物 I 的 Q 模块。然而，具体组装步骤所涉及的因素尚未完全确定。在这里，我们分离出了一种拟南芥突变体，即氯呼吸还原 9 (crr9)，其 NDH 活性有缺陷。 CRR9 基因编码一种新型基质蛋白，没有任何已知的功能域或基序。 CRR9 在蓝藻和陆地植物中高度保守，但在绿藻中则不然，因为绿藻没有叶绿体 NDH。类囊体蛋白的蓝色非变性 PAGE 和免疫印迹分析表明，crr9 中亚复合物 A 的形成受到损害，CRR9 是 NdhK（一种亚复合物 A 亚基）在基质中 NDH 组装中间体中积累所必需的。此外，基质部分的二维清晰天然/SDS-PAGE 分析表明 NdhM 掺入 NDH 组装中间复合物 400 在 crr9 中受到损害。这些结果表明 CRR9 是形成 NDH 亚复合物 A 所需的新因子。
In vascular plants, the chloroplast NADH dehydrogenase-like (NDH) complex, a homolog of respiratory NADH:quinone oxidoreductase (Complex I), mediates plastoquinone reduction using ferredoxin as an electron donor in cyclic electron transport around PSI in the thylakoid membrane. In angiosperms, chloroplast NDH is composed of five subcomplexes and forms a supercomplex with PSI. The modular assembly of stroma-protruded subcomplex A, which corresponds to the Q module of Complex I, was recently reported. However, the factors involved in the specific assembly steps have not been completely identified. Here, we isolated an Arabidopsis mutant, chlororespiratory reduction 9 (crr9), defective in NDH activity. The CRR9 gene encodes a novel stromal protein without any known functional domains or motifs. CRR9 is highly conserved in cyanobacteria and land plants but not in green algae, which do not have chloroplast NDH. Blue native-PAGE and immunoblot analyses of thylakoid proteins indicated that formation of subcomplex A was impaired in crr9 CRR9 was specifically required for the accumulation of NdhK, a subcomplex A subunit, in NDH assembly intermediates in the stroma. Furthermore, two-dimensional clear native/SDS-PAGE analysis of the stroma fraction indicated that incorporation of NdhM into NDH assembly intermediate complex 400 was impaired in crr9 These results suggest that CRR9 is a novel factor required for the formation of NDH subcomplex A.