Repression of sigK Intervening (skin) Element Gene Expression by the CI-Like Protein SknR and Effect of SknR Depletion on Growth of Bacillus subtilis Cells
Repression of sigK Intervening (skin) Element Gene Expression by the CI-Like Protein SknR and Effect of SknR Depletion on Growth of Bacillus subtilis Cells
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DOI：
10.1128/jb.00625-10
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发表时间：
2010-12-01
影响因子：
3.2
通讯作者：
Sato, Tsutomu
中科院分区：
文献类型：
--
作者：
Kimura, Tatsu;Amaya, Yukie;Sato, Tsutomu
通过DNA重排从染色体上切除枯草芽孢杆菌噬菌体DNA样sigK插入（皮肤）元件（48 kb），并在孢子形成期间在染色体上产生复合基因sigK（spoIIIC和spoIVCB）。在这项研究中，我们首先关注sknR（皮肤阻遏物）的作用，它与缺陷噬菌体PBSX的Xre阻遏物编码基因具有同源性。SknR的缺失导致yqaF和yqaN之间的区域（yqaF-yqaN操纵子）的过表达和B中的生长缺陷。枯草杆菌。点突变分析和电泳迁移率变动分析（EMSA）表明，SknR的功能作为一个负调节基因表达的yqaF-yqaN操纵子的皮肤元素通过直接相互作用与运营商的2倍对称性位于sknR和yqaF之间的基因间区域。缺失分析显示，SknR缺失的致死效应与yqaH和yqaM的过表达有关，其产物先前被报道分别与DnaA和DnaC相关。此外，yqaH或yqaM的过度表达引起细胞分裂和异常染色体分离，这表明这些蛋白质的过度产生抑制DNA复制。此外，yqaM的过表达抑制复制的起始。总之，这些数据表明，B。枯草杆菌表皮因子携带致死基因，这些基因由sknR的缺失诱导。
The Bacillus subtilis phage DNA-like sigK intervening (skin) element (48 kb) is excised from the chromosome by DNA rearrangement, and a composite gene, sigK (spoIIIC and spoIVCB), is created on the chromosome during sporulation. In this study, we first focused on the role of sknR (skin repressor), which has homology with the gene encoding the Xre repressor of defective phage PBSX. The depletion of SknR caused overexpression of the region between yqaF and yqaN (the yqaF-yqaN operon) and a growth defect in B. subtilis. Point mutation analysis and an electrophoretic mobility shift assay (EMSA) suggested that SknR functions as a negative regulator of gene expression in the yqaF-yqaN operon of the skin element through direct interaction with operators of 2-fold symmetry located in the intergenic region between sknR and yqaF. Deletion analysis revealed that the lethal effect of depletion of SknR was related to overexpression of yqaH and yqaM, whose products were previously reported to associate with DnaA and DnaC, respectively. Furthermore, overexpression of either yqaH or yqaM caused cell filamentation and abnormal chromosome segregation, which suggested that overproduction of these proteins inhibits DNA replication. Moreover, overexpression of yqaM inhibited the initiation of replication. Taken together, these data demonstrate that the B. subtilis skin element carries lethal genes, which are induced by the depletion of sknR.