Enzymatic diversity of the Clostridium thermocellum cellulosome is crucial for the degradation of crystalline cellulose and plant biomass.
Enzymatic diversity of the Clostridium thermocellum cellulosome is crucial for the degradation of crystalline cellulose and plant biomass.
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DOI：
10.1038/srep35709
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发表时间：
2016-10-19
影响因子：
4.6
通讯作者：
Hirano N
中科院分区：
文献类型：
--
作者：
Hirano K;Kurosaki M;Nihei S;Hasegawa H;Shinoda S;Haruki M;Hirano N
纤维素是一种由多种多糖降解酶和支架蛋白组成的超分子多酶复合体。与支架蛋白结合的纤维素体酶协同降解结晶纤维素。在这里，我们报道了用40种纤维素体成分和与9种酶分子结合的全长支架蛋白体外重建热梭菌纤维素体。这些成分分别用小麦无生殖细胞蛋白合成系统合成并纯化。根据天然纤维素中3、12、30和40个组分的含量分别重组纤维素复合物。酶饱和复合物的活性表明，酶的种类越多，对降解结晶纤维素和脱木质素秸秆产生的协同作用越大。令人惊讶的是，尽管酶饱和复合物在降解结晶纤维素方面表现出最大的协同作用，但含有少于9个酶分子的不完全酶复合物在降解脱木质素稻草方面比酶饱和复合物更有效。这些结果表明，更大的纤维素酶多样性对于晶体纤维素和植物生物量的降解至关重要，并且纤维素体对不同底物的有效降解不仅需要不同的酶组成，还需要不同的纤维素结构。
The cellulosome is a supramolecular multienzyme complex comprised of a wide variety of polysaccharide-degrading enzymes and scaffold proteins. The cellulosomal enzymes that bind to the scaffold proteins synergistically degrade crystalline cellulose. Here, we report in vitro reconstitution of the Clostridium thermocellum cellulosome from 40 cellulosomal components and the full-length scaffoldin protein that binds to nine enzyme molecules. These components were each synthesized using a wheat germ cell-free protein synthesis system and purified. Cellulosome complexes were reconstituted from 3, 12, 30, and 40 components based on their contents in the native cellulosome. The activity of the enzyme-saturated complex indicated that greater enzymatic variety generated more synergy for the degradation of crystalline cellulose and delignified rice straw. Surprisingly, a less complete enzyme complex displaying fewer than nine enzyme molecules was more efficient for the degradation of delignified rice straw than the enzyme-saturated complex, despite the fact that the enzyme-saturated complex exhibited maximum synergy for the degradation of crystalline cellulose. These results suggest that greater enzymatic diversity of the cellulosome is crucial for the degradation of crystalline cellulose and plant biomass, and that efficient degradation of different substrates by the cellulosome requires not only a different enzymatic composition, but also different cellulosome structures.
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影响因子：
3.2
作者：
Ahsan, MM;Kimura, T;Ohmiya, K
通讯作者：
Ohmiya, K
DOI：
10.1073/pnas.1015006108
发表时间：
2011-03-29
影响因子：
11.1
作者：
Bras, Joana L. A.;Cartmell, Alan;Gilbert, Harry J.
通讯作者：
Gilbert, Harry J.
影响因子：
4
作者：
Deng, Kai;Takasuka, Taichi E.;Northen, Trent R.
通讯作者：
Northen, Trent R.
影响因子：
4.1
作者：
FONTES, CMGA;HAZLEWOOD, GP;GILBERT, HJ
通讯作者：
GILBERT, HJ
影响因子：
5
作者：
Hayashi, H;Takehara, M;Ohmiya, K
通讯作者：
Ohmiya, K