Polar Positioning of a Conjugation Protein from the Integrative and Conjugative Element ICEBs1 of Bacillus subtilis
Polar Positioning of a Conjugation Protein from the Integrative and Conjugative Element ICEBs1 of Bacillus subtilis
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DOI：
10.1128/jb.00860-09
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发表时间：
2010-01-01
影响因子：
3.2
通讯作者：
Grossman, Alan D.
中科院分区：
文献类型：
--
作者：
Berkmen, Melanie B.;Lee, Catherine A.;Grossman, Alan D.
ICEBs1是在枯草芽孢杆菌染色体上发现的一个整合和共轭元件。ICEBs1编码其切除和转移到受体细胞所需的功能。我们发现ICEBs1基因conE（以前的yddE）是缀合所必需的，并且ICEBs1的缀合转移需要一个保守的atp酶基序conE。ConE属于ATPases的HerA/FtsK超家族，该家族包括已被充分表征的蛋白FtsK、SpoIIIE、VirB4和VirD4。我们发现，在ICEBs1供体细胞中，ConE-GFP（绿色荧光蛋白）融合主要在细胞两极与膜相关。至少有一种ICEBs1产物可能与ConE相互作用，将其靶向到膜和细胞极点，因为在缺乏ICEBs1的菌株中，ConE- gfp分散在整个细胞质中。我们还可视化了ICEBs1的亚细胞位置。当整合到染色体中时，ICEBs1沿着细胞的长度位于细胞中部附近，这是该染色体区域的特征位置。切除后，ICEBs1更常出现在细胞极附近。切除ICEBs1也会导致至少一个重复体成分的位置改变。综上所述，我们的研究结果表明，ConE是ICEBs1偶联机制的关键组成部分，枯草芽孢杆菌ICEBs1的偶联转移可能始于供体细胞极，并且ICEBs1影响复制体的亚细胞位置。
ICEBs1 is an integrative and conjugative element found in the chromosome of Bacillus subtilis. ICEBs1 encodes functions needed for its excision and transfer to recipient cells. We found that the ICEBs1 gene conE (formerly yddE) is required for conjugation and that conjugative transfer of ICEBs1 requires a conserved ATPase motif of ConE. ConE belongs to the HerA/FtsK superfamily of ATPases, which includes the well-characterized proteins FtsK, SpoIIIE, VirB4, and VirD4. We found that a ConE-GFP (green fluorescent protein) fusion associated with the membrane predominantly at the cell poles in ICEBs1 donor cells. At least one ICEBs1 product likely interacts with ConE to target it to the membrane and cell poles, as ConE-GFP was dispersed throughout the cytoplasm in a strain lacking ICEBs1. We also visualized the subcellular location of ICEBs1. When integrated in the chromosome, ICEBs1 was located near midcell along the length of the cell, a position characteristic of that chromosomal region. Following excision, ICEBs1 was more frequently found near a cell pole. Excision of ICEBs1 also caused altered positioning of at least one component of the replisome. Taken together, our findings indicate that ConE is a critical component of the ICEBs1 conjugation machinery, that conjugative transfer of ICEBs1 from B. subtilis likely initiates at a donor cell pole, and that ICEBs1 affects the subcellular position of the replisome.