Identification and sequence analysis of the ribosomal DNA promoter region of Crithidia fasciculata.
Identification and sequence analysis of the ribosomal DNA promoter region of Crithidia fasciculata.
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Crithidia fasciculata 核糖体 DNA 启动子区的鉴定和序列分析。
DOI：
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发表时间：
1990
影响因子：
14.9
通讯作者：
A. W. Cornelissen
中科院分区：
文献类型：
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作者：
E. Grondal;R. Evers;A. W. Cornelissen
通过Northern印迹和核连续分析，我们已经确定了丛枝克里斯虫大核糖体DNA重复单位的启动子区域。这些数据表明，转录开始于18S rRNA基因上游约1kb。该区域的S1保护实验和序列分析导致了起始点的精确定位。我们一直不能通过直接比较其他真核生物的胚道RNA聚合酶I启动子区域和类似的启动子区域来确定保守序列元件(S)，甚至不能与更接近的动质体种布氏锥虫的启动子区域进行比较。在其他真核生物中也发现的启动子区域的初级序列中缺乏同源性，这可能解释了观察到的体内和体外rDNA转录的物种特异性，因为这存在于启动因子(S)和核心启动子域的相互作用中。
We have identified the promoter region of the large ribosomal DNA repeat unit of Crithidia fasciculata by northern blotting and nuclear run-on analyses. These data show that transcription starts approximately 1 kb upstream of the 18S rRNA gene. S1 protection experiments and sequence analysis of this area resulted in a precise localization of the start site. We have been unable to identify conserved sequence element(s) by a direct comparison of the crithidial RNA polymerase I promoter region and similar promoter regions of other eukaryotes; not even to the promoter region of the more closely related kinetoplastid species, Trypanosoma brucei. The absence of homology within the primary sequence of the promoter region, which is also found in other eukaryotes, might explain the observed species specificity of in vivo and in vitro rDNA transcription, since this resides in the interaction of initiation factor(s) and the core promoter domain.