Expression of the endogenous type II secretion pathway in Escherichia coli leads to chitinase secretion
Expression of the endogenous type II secretion pathway in Escherichia coli leads to chitinase secretion
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DOI：
10.1093/emboj/19.24.6697
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发表时间：
2000-12-15
期刊：
影响因子：
11.4
通讯作者：
Pugsley, AP
中科院分区：
文献类型：
--
作者：
Francetic, O;Belin, D;Pugsley, AP
大肠杆菌K-12是最广泛使用的实验室细菌，尽管拥有编码II型分泌机制（分泌物）的染色体基因，但在标准生长条件下，大肠杆菌K-12不向细胞外培养基分泌蛋白质。我们发现，在野生型大肠杆菌K-12中，编码大部分分泌成分的主染色体gsp位点的两个操纵子的发散转录被核结构蛋白H-NS沉默。在缺乏H-NS的突变体中，克隆在中等拷贝数质粒上的分泌基因表达并促进内源性、共调节的内源性几丁质酶ChiA的有效分泌。这是首次在大肠杆菌K-12中发现内源性细胞外蛋白的分泌。
Escherichia coli K-12, the most widely used laboratory bacterium, does not secrete proteins into the extracellular medium under standard growth conditions, despite possessing chromosomal genes encoding a putative type II secretion machinery (secreton). We show that in wild-type E.coli K-12, divergent transcription of the two operons in the main chromosomal gsp locus, encoding the majority of the secreton components, is silenced by the nucleoid-structuring protein H-NS. In mutants lacking H-NS, the secreton genes cloned on a moderate-copy-number plasmid are expressed and promote efficient secretion of the endogenous, co-regulated endochitinase ChiA. This is the first time that secretion of an endogenous extracellular protein has been demonstrated in E.coli K-12.