Plasmid copy-number control and better-than-random segregation genes of pSM19035 share a common regulator
Plasmid copy-number control and better-than-random segregation genes of pSM19035 share a common regulator
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DOI：
10.1073/pnas.97.2.728
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发表时间：
2000-01-18
影响因子：
11.1
通讯作者：
Ceglowski, P
中科院分区：
文献类型：
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作者：
de la Hoz, AB;Ayora, S;Ceglowski, P
在枯草芽孢杆菌细胞中，广宿主范围和低拷贝数质粒pSM 19035的拷贝数控制和优于随机分离基因的转录起始受到自动调节的pSM 19035编码的ω产物的阻遏。cops（Pcop 1和Pcop 2）、delta（P delta）和omega（P omega）基因的启动子已经被定位。这些启动子嵌入一组7个拷贝的7-bp同向重复序列中，或嵌入由两个7-bp同向重复序列和一个7-bp反向重复序列组成的嵌段中;嵌段存在两次或三次。ω蛋白与Pcop 1、Pcop 2、P δ和P ω启动子上的重复序列的协同结合通过不将sigma（A）RNAP从启动子中排除的机制抑制转录起始。这些结果表明，ω蛋白调节质粒的维持，一方面通过控制拷贝数，另一方面通过调节优于随机分离所需的蛋白质的量。
Transcription initiation of the copy-number control and better-than-random segregation genes of the broad-host-range and low-copy-number plasmid pSM19035 are subjected to repression by the autoregulated pSM19035-encoded omega product in Bacillus subtilis cells. The promoters of the cops (Pcop1 and Pcop2), delta (P delta), and omega (P omega) genes have been mapped. These promoters are embedded in a set of either seven copies of a 7-bp direct repeat or in a block consisting of two 7-bp direct repeats and one 7-bp inverted repeat; the blocks are present either two or three times. The cooperative binding of omega protein to the repeats on the Pcop1, Pcop2, P delta, and P omega promoters represses transcription initiation by a mechanism that does not exclude sigma(A)RNAP from the promoters. These results indicate that omega protein regulates plasmid maintenance by controlling the copy number on the one hand and by regulating the amount of proteins required for better-than-random segregation on the other hand.