Rubisco small subunits from the unicellular green alga Chlamydomonas complement Rubisco-deficient mutants of Arabidopsis.
Rubisco small subunits from the unicellular green alga Chlamydomonas complement Rubisco-deficient mutants of Arabidopsis.
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DOI：
10.1111/nph.14414
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发表时间：
2017-04
期刊：
影响因子：
--
通讯作者：
McCormick AJ
中科院分区：
文献类型：
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作者：
Atkinson N;Leitão N;Orr DJ;Meyer MT;Carmo-Silva E;Griffiths H;Smith AM;McCormick AJ
将藻类碳浓缩机制（CCM）的组分导入高等植物叶绿体可以提高光合生产力。一个关键的成分是含有Rubisco的蛋白核，它需要最大限度地减少CO2逆扩散，以提高CCM的运行效率。拟南芥中的Rubisco被重新工程化，以并入被认为是Rubisco募集到蛋白核所必需的序列元件，即藻类Rubisco小亚基（SSU，由rbcS编码）或仅表面暴露的藻类SSU α螺旋。拟南芥rbcs突变体表达含有来自莱茵衣藻的SSU α-螺旋的“类蛋白核能力”嵌合拟南芥SSU，其叶片可以形成具有与天然Rubisco类似的催化性质的杂合Rubisco复合物，表明α-螺旋是催化中性的。产生接近野生型水平的杂合Rubisco的互补拟南芥rbcs突变体的生长和光合性能与野生型对照相似。表达衣原体SSU的拟南芥rbcs突变体在Rubisco催化、光合作用和生长方面与野生型植物不同。这证实了SSU在影响Rubisco催化性质中的作用。另见Sharwood对这篇文章的评论，214：496-499。
Introducing components of algal carbon concentrating mechanisms (CCMs) into higher plant chloroplasts could increase photosynthetic productivity. A key component is the Rubisco‐containing pyrenoid that is needed to minimise CO 2 retro‐diffusion for CCM operating efficiency. Rubisco in Arabidopsis was re‐engineered to incorporate sequence elements that are thought to be essential for recruitment of Rubisco to the pyrenoid, namely the algal Rubisco small subunit (SSU, encoded by rbcS) or only the surface‐exposed algal SSU α‐helices. Leaves of Arabidopsis rbcs mutants expressing ‘pyrenoid‐competent’ chimeric Arabidopsis SSUs containing the SSU α‐helices from Chlamydomonas reinhardtii can form hybrid Rubisco complexes with catalytic properties similar to those of native Rubisco, suggesting that the α‐helices are catalytically neutral. The growth and photosynthetic performance of complemented Arabidopsis rbcs mutants producing near wild‐type levels of the hybrid Rubisco were similar to those of wild‐type controls. Arabidopsis rbcs mutants expressing a Chlamydomonas SSU differed from wild‐type plants with respect to Rubisco catalysis, photosynthesis and growth. This confirms a role for the SSU in influencing Rubisco catalytic properties. See also the Commentary on this article by Sharwood, 214: 496–499.