Evers R, Cornelissen A W
Max-Planck-Institut für Biologie, Molecular Parasitology Unit, Tübingen, FRG.
Nucleic Acids Res. 1990 Sep 11;18(17):5089-95. doi: 10.1093/nar/18.17.5089.
We have previously described the trypanosomal gene encoding the largest subunit of RNA polymerase II (RNAP II) and found that two almost identical genes are encoded within the Trypanosoma brucei genome. Here we show by Southern analyses that the 5' breakpoint between both loci is located approximately 7.5 kb upstream of the RNAP II genes. Northern analyses revealed that the 5' duplicated segment contains at least four other genes, which are transcribed in both bloodstream and procyclic trypanosomes. The gene located immediately upstream of the RNAP II gene in both loci was characterized by sequence analyses. The deduced amino acid sequences show a high degree of similarity to the catalytic subunit of protein phosphatase class 1 (PP1) genes. S1 mapping provided strong evidence in support of the fact that the PP1 and RNAP II genes belong to a single transcription unit.
我们之前已经描述了编码RNA聚合酶II（RNAP II）最大亚基的锥虫基因，并发现布氏锥虫基因组中编码了两个几乎相同的基因。在此，我们通过Southern分析表明，两个基因座之间的5'断点位于RNAP II基因上游约7.5 kb处。Northern分析显示，5'重复片段至少包含另外四个基因，这些基因在血流型和前循环型锥虫中均有转录。通过序列分析对两个基因座中紧邻RNAP II基因上游的基因进行了表征。推导的氨基酸序列与蛋白磷酸酶1类（PP1）基因的催化亚基具有高度相似性。S1图谱分析提供了有力证据，支持PP1和RNAP II基因属于单个转录单元这一事实。
