CELL CYCLE-DEPENDENT TRANSCRIPTION FROM THE GID AND MIOC PROMOTERS OF ESCHERICHIA-COLI
CELL CYCLE-DEPENDENT TRANSCRIPTION FROM THE GID AND MIOC PROMOTERS OF ESCHERICHIA-COLI
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DOI：
10.1128/jb.176.6.1609-1615.1994
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发表时间：
1994-03-01
影响因子：
3.2
通讯作者：
OKAZAKI, T
中科院分区：
文献类型：
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作者：
OGAWA, T;OKAZAKI, T
GID和MioC启动子位于大肠杆菌染色体(ORIC)复制起点附近，其转录调控微小染色体复制的启动。在对温度敏感的dna C突变株的同步培养中，在不同的时间对这两个启动子在染色体上的转录量进行了定量。GID启动子的转录在复制开始之前最活跃，在复制开始后，在与DAM甲基转移酶的ORIC区隔离的时间内，转录被抑制。另一方面，mioc启动子的转录在启动前被抑制，启动后抑制解除，在gid转录恢复之前。GID和MioC启动子对转录的严格调控可能分别参与了对染色体复制的正向控制和负向控制，就像对微染色体复制所提出的那样。Dna A蛋白参与了对Mioc转录的抑制，表明Dna A蛋白的活性在细胞周期中发生变化。
Transcription from the gid and mioC promoters, which neighbor the origin of replication of the Escherichia coli chromosome (oriC), has been implicated in the control of initiation of replication of minichromosomes. The amounts of transcripts from these two promoters on the chromosome were quantified at various times in a synchronized culture of a temperature-sensitive dnaC mutant strain. Transcription from the gid promoter was most active before the initiation of replication and was inhibited after initiation, during the time corresponding to the period of sequestration of the oriC region from the dam methyltransferase. On the other hand, transcription from the mioC promoter was inhibited before initiation and the inhibition mas relieved after initiation prior to the recovery of gid transcription. The strict regulation of transcription from the gid and mioC promoters may be involved in positive and negative control of chromosomal replication, respectively, as has been suggested for minichromosome replication. The DnaA protein was involved in repression of mioC transcription, indicating that the activity of the DnaA protein changes during the cell cycle.