Dempsey W B
Research Service, Veterans Administration Medical Center, TX.
Mol Gen Genet. 1987 Oct;209(3):533-44. doi: 10.1007/BF00331160.
Single-stranded RNA probes were used to study the regulation of plasmid transfer in the infectious antibiotic resistance plasmid R100. Transcription of the positive transfer control gene traJ of R100 appears to be initiated continuously. In the presence of finO, the traJ transcript is 235 bases long, and in the absence of finO it is 1050. These sizes are strain specific. finO increases four-to tenfold the amount of the transcript from the finP gene that is detectable in cells containing R100, R136, or the sex factor F. The size of the principal finP transcript from R100 as determined on Northern blots is 105 bases. A secondary transcript with a size of 180 bases was detected in small amounts in R100 extracts. The finP transcript size was also determined by nuclease protection experiments. In this case the size was 74 bases. The 5' ends of the finP and traJ transcripts were located by primer extension experiments. A new model of FinO/P control is proposed.
单链RNA探针被用于研究感染性抗生素抗性质粒R100中质粒转移的调控。R100的正向转移控制基因traJ的转录似乎是持续起始的。在存在finO的情况下，traJ转录本长度为235个碱基，而在不存在finO的情况下，其长度为1050个碱基。这些长度是菌株特异性的。finO使在含有R100、R136或性因子F的细胞中可检测到的finP基因转录本的量增加4到10倍。在Northern印迹上确定的来自R100的主要finP转录本的大小为105个碱基。在R100提取物中少量检测到大小为180个碱基的次要转录本。finP转录本的大小也通过核酸酶保护实验确定。在这种情况下，大小为74个碱基。通过引物延伸实验确定了finP和traJ转录本的5'末端。提出了一种FinO/P控制的新模型。
