Chelm B K, Gray P W, Hallick R B
Biochemistry. 1978 Oct 3;17(20):4239-44. doi: 10.1021/bi00613a020.
RNA transcription from defined regions of the Euglena gracilis chloroplast genome has been characterized by hybridization of total cell RNA to 3H-labeled chloroplast DNA restriction endonuclease fragments. Chloroplast DNA was digested into five fragments of 53, 35, 25, 10, and 6.9 kilobase pairs (kbp) with Pst1. The 53-kbp DNA was also subfractionated by BamHI digestion. The extent of transcription of the Pst1 fragments was found to be 30, 17, 15, 2.2, and 2.3 kb of RNA, respectively. The total amount of RNA transcription of 67 kb represents 26% to the double-strand information content of the genome. Transcribed regions are dispersed throughout the DNA. The RNA transcripts are present in two major abundance classes in the cell. High abundance transcripts of approximately 10(6) copies/cell were mapped in the rRNA gene region of the 53-kbp fragment and in the 35-kbp fragment. Low abundance transcripts of approximately 1000--4000 copies/cell were mapped in all five Pst fragments.
通过将总细胞RNA与3H标记的叶绿体DNA限制性内切酶片段杂交，对纤细裸藻叶绿体基因组特定区域的RNA转录进行了表征。用Pst1将叶绿体DNA消化成5个片段，大小分别为53、35、25、10和6.9千碱基对（kbp）。53-kbp的DNA也通过BamHI消化进行了进一步细分。发现Pst1片段的转录程度分别为30、17、15、2.2和2.3 kb的RNA。67 kb的RNA转录总量占基因组双链信息含量的26%。转录区域分散在整个DNA中。RNA转录本在细胞中存在于两个主要丰度类别中。大约10(6)拷贝/细胞的高丰度转录本定位在53-kbp片段的rRNA基因区域和35-kbp片段中。大约1000 - 4000拷贝/细胞的低丰度转录本定位在所有五个Pst片段中。
