A new locus affects cell motility, cellulose binding, and degradation by Cytophaga hutchinsonii
A new locus affects cell motility, cellulose binding, and degradation by Cytophaga hutchinsonii
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一个新的位点影响细胞运动、纤维素结合和哈钦森噬细胞菌的降解
DOI：
10.1007/s00253-012-4051-y
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发表时间：
2012-10-01
影响因子：
5
通讯作者：
Lu, Xuemei
中科院分区：
文献类型：
--
作者：
Ji, Xiaofei;Xu, Yuanxi;Lu, Xuemei
Cytophagahutchinsonii是一种革兰氏阴性的滑行细菌，它可以通过一种新的策略快速降解结晶纤维素，而不需要任何可识别的加工纤维素酶。其结合和降解纤维素的机理至今仍是一个谜。本研究对C.首次报道了用基于mariner的转座子HimarEm 3和基于oriC的携带抗生素抗性基因cfxA或tetQ的质粒进行基因互补的方法对hutchinsonii进行诱变，为细菌的诱变和遗传操作提供了有价值的工具。突变体A-4在基因CHU_0134中具有转座子突变，其编码假定的硫醇-二硫键异构酶，表现出细胞运动性和纤维素降解的缺陷。A-4的纤维素结合能力仅为野生型菌株的一半，而A-4的无细胞上清液和完整细胞表面上的内切纤维素酶活性下降了40%。十二烷基硫酸钠聚丙烯酰胺凝胶电泳结果表明，在A-4菌株中，大多数与纤维素结合的蛋白质都显著减少或消失，其中包括一些Gld蛋白和假想蛋白，表明这些蛋白质可能在细菌的细胞运动和纤维素结合降解中起重要作用。
Cytophaga hutchinsonii is a Gram-negative gliding bacterium, which can rapidly degrade crystalline cellulose via a novel strategy without any recognizable processive cellulases. Its mechanism of cellulose binding and degradation is still a mystery. In this study, the mutagenesis of C. hutchinsonii with the mariner-based transposon HimarEm3 and gene complementation with the oriC-based plasmid carrying the antibiotic resistance gene cfxA or tetQ were reported for the first time to provide valuable tools for mutagenesis and genetic manipulation of the bacterium. Mutant A-4 with a transposon mutation in gene CHU_0134, which encodes a putative thiol-disulfide isomerase exhibits defects in cell motility and cellulose degradation. The cellulose binding ability of A-4 was only half of that of the wild-type strain, while the endo-cellulase activity of the cell-free supernatants and on the intact cell surface of A-4 decreased by 40%. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of proteins binding to cellulose in the outer membrane showed that most of them were significantly decreased or disappeared in A-4 including some Gld proteins and hypothetical proteins, indicating that these proteins might play an important role in cell motility and cellulose binding and degradation by the bacterium.