A novel non-homologous recombination-mediated mechanism for Escherichia coli unilateral flagellar phase variation.
A novel non-homologous recombination-mediated mechanism for Escherichia coli unilateral flagellar phase variation.
复制标题
大肠杆菌单侧鞭毛相位变异的新型非同源重组介导机制
DOI：
10.1093/nar/gks040
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发表时间：
2012-05
影响因子：
14.9
通讯作者：
Wang L
中科院分区：
文献类型：
--
作者：
Liu B;Hu B;Zhou Z;Guo D;Guo X;Ding P;Feng L;Wang L
鞭毛通过趋化性、粘附性和侵袭性促进细菌的毒力。鞭毛阶段的变化被认为有助于细菌逃避宿主的免疫反应。本研究通过全基因组测序和基因缺失分析，对编码大肠杆菌H17鞭毛蛋白的Flna基因进行了检测。在大肠杆菌H3、H47和H17菌株中已经报道了单侧鞭毛相变异，尽管H17菌株的相变异机制以前还不清楚。阶段变异分析表明，H17株鞭毛阶段的变异是由于含有Fla基因的∼35 kbDNA区域从不同的切除点缺失所致。两步聚合酶链式反应证实了该35 kb区存在共价闭合的染色体外环状结构。缺失和互补试验表明，Int1157整合酶是一种酪氨酸重组酶，介导了该区域的切除。与大多数酪氨酸重组酶不同，Int1157被认为可以识别不同的位点，并介导非同源DNA序列之间的重组。这是非同源重组介导鞭毛相变化的首次报道。
Flagella contribute to the virulence of bacteria through chemotaxis, adhesion to and invasion of host surfaces. Flagellar phase variation is believed to facilitate bacterial evasion of the host immune response. In this study, the flnA gene that encodes Escherichia coli H17 flagellin was examined by whole genome sequencing and genetic deletion analysis. Unilateral flagellar phase variation has been reported in E. coli H3, H47 and H17 strains, although the mechanism for phase variation in the H17 strain has not been previously understood. Analysis of phase variants indicated that the flagellar phase variation in the H17 strain was caused by the deletion of an ∼35 kb DNA region containing the flnA gene from diverse excision sites. The presence of covalently closed extrachromosomal circular forms of this excised 35 kb region was confirmed by the two-step polymerase chain reaction. The deletion and complementation test revealed that the Int1157 integrase, a tyrosine recombinase, mediates the excision of this region. Unlike most tyrosine recombinases, Int1157 is suggested to recognize diverse sites and mediate recombination between non-homologous DNA sequences. This is the first report of non-homologous recombination mediating flagellar phase variation.
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影响因子：
6.7
作者：
Baker, Stephen;Hardy, Jonathan;Sanderson, Kenneth E;Quail, Michael;Goodhead, Ian;Kingsley, Robert A;Parkhill, Julian;Stocker, Bruce;Dougan, Gordon
通讯作者：
Dougan, Gordon
影响因子：
9.4
作者：
IBRAHIM, GF;FLEET, GH;WALKER, RA
通讯作者：
WALKER, RA
影响因子：
3.2
作者：
Ratiner, YA
通讯作者：
Ratiner, YA
影响因子：
2.1
作者：
RATINER, YA
通讯作者：
RATINER, YA
影响因子：
2.1
作者：
RATINER, YA
通讯作者：
RATINER, YA