CONTROL OF COLE1 DNA-REPLICATION - THE ROP GENE-PRODUCT NEGATIVELY AFFECTS TRANSCRIPTION FROM THE REPLICATION PRIMER PROMOTER
CONTROL OF COLE1 DNA-REPLICATION - THE ROP GENE-PRODUCT NEGATIVELY AFFECTS TRANSCRIPTION FROM THE REPLICATION PRIMER PROMOTER
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DOI：
10.1073/pnas.79.20.6313
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发表时间：
1982-01-01
期刊：
影响因子：
--
通讯作者：
POLISKY, B
中科院分区：
文献类型：
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作者：
CESARENI, G;MUESING, MA;POLISKY, B
ColE 1和pMB 1质粒复制所必需的600个碱基对区域含有2个启动子，负责合成2个RNA分子，这2个RNA分子对拷贝数控制至关重要。一个启动子指导引物RNA前体的合成。第二个启动子指导小RNA分子RNA 1的合成，RNA 1反式作用以抑制RNA引物前体的加工。每个启动子与β-半乳糖苷酶结构基因。噬菌体。溶原菌中RNA 1启动子的表达不受存在于细胞中的野生型pMB 1或ColE 1质粒的影响。然而，来自RNA引物启动子的转录被反式作用质粒基因产物的产物抑制，该产物被命名为rop（引物的阻遏物）。rop基因定位于复制起点下游编码63个氨基酸的多肽的区域，该多肽的序列在pMB 1和ColE 1中完全保守。该多肽可能是rop基因的产物，它可能通过调节引物RNA前体转录的起始来调节质粒DNA的复制。
A 600-base-pair region essential for ColE1 and pMB1 plasmid replication [in Escherichia coli] contains 2 promoters responsible for the synthesis of 2 RNA molecules central to copy number control. One promoter directs synthesis of the primer RNA precursor. The 2nd promoter directs the synthesis of a small RNA molecule, RNA1, which acts in trans to inhibit processing of the RNA primer precursor. Each promoter was fused to the .beta.-galactosidase structural gene contained in a .lambda. phage. Expression of the RNA1 promoter in lysogens is not influenced by the presence of wild-type pMB1 or ColE1 plasmids residing in the cell. Transcription from the RNA primer promoter, however, is repressed by the product of a trans-acting plasmid gene product, which was designated rop (for repressor of primer). The rop gene maps downstream from the replication origin in a region that encodes a polypeptide of 63 amino acids whose sequence is completely conserved in pMB1 and ColE1. This polypeptide is probably the rop gene product and it may regulate plasmid DNA replication by modulating the initiation of transcription of the primer RNA precursor.