DnaA and LexA Proteins Regulate Transcription of the uvrB Gene in Escherichia coli: The Role of DnaA in the Control of the SOS Regulon.
DnaA and LexA Proteins Regulate Transcription of the uvrB Gene in Escherichia coli: The Role of DnaA in the Control of the SOS Regulon.
复制标题
DOI：
10.3389/fmicb.2018.01212
复制
发表时间：
2018
影响因子：
5.2
通讯作者：
Morigen
中科院分区：
文献类型：
--
作者：
Wurihan;Gezi;Brambilla E;Wang S;Sun H;Fan L;Shi Y;Sclavi B;Morigen
uvrB基因属于SOS网络，编码核苷酸切除修复的关键组分。uvrB启动子区含有三个鉴定的启动子，具有四个莱克萨结合位点、一个共有位点和六个潜在的DnaA结合位点。与野生型细胞相比，在Δ莱克萨Δ苏拉细胞和dnaAA 345 S细胞中均观察到染色体uvrB基因转录增加了3倍以上，在Δ莱克萨Δ苏拉dnaAA 345 S细胞中增加了5倍。uvrB启动子区的全部活性需要uvrBp 1 -2和uvrBp 3启动子，并被DnaA和莱克萨蛋白抑制。莱克萨在uvrBp 1 -2启动子处与LexA-box 1紧密结合，而与DnaA的存在无关，并且这种结合对于uvrBp 1 -2启动子的控制是重要的。然而，DnaA和莱克萨竞争结合和调节uvrBp 3启动子，其中DnaA-box 6与LexA-box 4重叠。uvrBp 3的转录调控主要依赖于DnaA-box 6。其他SOS调节子基因（如recN和dinJ）的转录也受到DnaA和莱克萨的抑制。有趣的是，在DnaAA 345 S突变体存在的情况下，莱克萨的缺失导致产生具有不完全复制、异常类核和缓慢生长的伸长细胞。我们建议，DnaA是一种调制器，通过限制SOS调节子的表达，在SOS反应过程中维持基因组的完整性。
The uvrB gene belongs to the SOS network, encoding a key component of the nucleotide excision repair. The uvrB promoter region contains three identified promoters with four LexA binding sites, one consensus and six potential DnaA binding sites. A more than threefold increase in transcription of the chromosomal uvrB gene is observed in both the ΔlexA ΔsulA cells and dnaAA345S cells, and a fivefold increase in the ΔlexA ΔsulA dnaAA345S cells relative to the wild-type cells. The full activity of the uvrB promoter region requires both the uvrBp1-2 and uvrBp3 promoters and is repressed by both the DnaA and LexA proteins. LexA binds tightly to LexA-box1 at the uvrBp1-2 promoter irrespective of the presence of DnaA and this binding is important for the control of the uvrBp1-2 promoter. DnaA and LexA, however, compete for binding to and regulation of the uvrBp3 promoter in which the DnaA-box6 overlaps with LexA-box4. The transcription control of uvrBp3 largely depends on DnaA-box6. Transcription of other SOS regulon genes, such as recN and dinJ, is also repressed by both DnaA and LexA. Interestingly, the absence of LexA in the presence of the DnaAA345S mutant leads to production of elongated cells with incomplete replication, aberrant nucleoids and slow growth. We propose that DnaA is a modulator for maintenance of genome integrity during the SOS response by limiting the expression of the SOS regulon.
登录
查看更多内容
DOI：
10.1007/bf00267322
发表时间：
1975-01-01
期刊：
MOLECULAR & GENERAL GENETICS
影响因子：
--
作者：
GEORGE, J;CASTELLAZZI, M;BUTTIN, G
通讯作者：
BUTTIN, G
影响因子：
64.5
作者：
BRAUN, RE;ODAY, K;WRIGHT, A
通讯作者：
WRIGHT, A
影响因子：
2.6
作者：
BOYE, E;LOBNEROLESEN, A
通讯作者：
LOBNEROLESEN, A
影响因子：
3.5
作者：
Ellermeier, CD;Janakiraman, A;Slauch, JM
通讯作者：
Slauch, JM
影响因子：
14.9
作者：
Margara LM;Fernández MM;Malchiodi EL;Argaraña CE;Monti MR
通讯作者：
Monti MR