Outer membrane proteins related to SusC and SusD are not required for Cytophaga hutchinsonii cellulose utilization
Outer membrane proteins related to SusC and SusD are not required for Cytophaga hutchinsonii cellulose utilization
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DOI：
10.1007/s00253-015-6555-8
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发表时间：
2015-04
影响因子：
5
通讯作者：
Yongtao Zhu;Kurt J. Kwiatkowski;Tengteng Yang;Sampada S. Kharade;C. Bahr;N. Koropatkin;Weifeng Liu;M. McBride
中科院分区：
文献类型：
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作者：
Yongtao Zhu;Kurt J. Kwiatkowski;Tengteng Yang;Sampada S. Kharade;C. Bahr;N. Koropatkin;Weifeng Liu;M. McBride
哈钦索细胞噬菌是拟杆菌门的一员，它利用一种新的细胞相关蛋白质来消化结晶纤维素。其他拟杆菌门依靠与淀粉利用系统（Sus）相关的细胞表面蛋白（SusC和SusD）结合低聚糖并将其导入外膜以进一步消化。这些细菌通常产生数十个susd样孔蛋白和susd样寡糖结合蛋白，以促进对各种多糖的利用。hutchinsoni擅长纤维素消化，它的基因组只有两个糖c样基因和两个糖d样基因。构建了单基因和多基因缺失来确定susc样基因和susd样基因是否在纤维素利用中起作用。缺乏全susc样基因和全susd样基因的突变体可以消化纤维素，并在纤维素和野生型细胞上生长。此外，重组表达的susd样蛋白CHU_0547和CHU_0554无法结合纤维素或β-葡聚糖半纤维素多糖。结果表明，拟杆菌对多糖的利用模式可能不适用于纤维素分解菌。hutchinsonii。
Cytophaga hutchinsonii, a member of the phylum Bacteroidetes, employs a novel collection of cell-associated proteins to digest crystalline cellulose. Other Bacteroidetes rely on cell surface proteins related to the starch utilization system (Sus) proteins SusC and SusD to bind oligosaccharides and import them across the outer membrane for further digestion. These bacteria typically produce dozens of SusC-like porins and SusD-like oligosaccharide-binding proteins to facilitate utilization of diverse polysaccharides.C. hutchinsoniispecializes in cellulose digestion and its genome has only twosusC-like genes and twosusD-like genes. Single and multiple gene deletions were constructed to determine if thesusC-like andsusD-like genes have roles in cellulose utilization. A mutant lacking allsusC-like and allsusD-like genes digested cellulose and grew on cellulose as well as wild-type cells. Further, recombinantly expressed SusD-like proteins CHU_0547 and CHU_0554 failed to bind cellulose or β-glucan hemicellulosic polysaccharides. The results suggest that the Bacteroidetes Sus paradigm for polysaccharide utilization may not apply to the cellulolytic bacteriumC. hutchinsonii.