Orum H, Nielsen H, Engberg J
Department of Biochemistry B, Panum Institute, University of Copenhagen, Denmark.
J Mol Biol. 1992 Sep 5;227(1):114-21. doi: 10.1016/0022-2836(92)90686-e.
We report the sequences of the genes encoding the small nuclear RNAs (snRNAs) U1 to U6 of the ciliate Tetrahymena thermophila. The genes of the individual snRNAs exist in two to six slightly different copies per haploid genome. Sequence analyses of the gene-flanking regions indicate that there are two classes of snRNA genes. Both classes are characterized by several conserved sequence elements, some of which are unique to each class and some of which are found in both classes. Comparison of the promoter structure of the snRNA genes of T. thermophila with the promoter structures of snRNA genes of other organisms revealed several similarities to plant snRNA genes. These similarities include the overall promoter architecture as well as specific sequence elements. The structural organization of the 3' flanking region of some of the T. thermophila snRNA genes is not observed in other organisms. This finding is discussed in relation to a possible role in snRNA 3'-end formation.
我们报道了嗜热四膜虫编码小核RNA（snRNA）U1至U6的基因序列。每个单倍体基因组中，各个snRNA的基因存在两到六个略有不同的拷贝。对基因侧翼区域的序列分析表明，存在两类snRNA基因。这两类基因都具有几个保守的序列元件，其中一些元件是每类所特有的，而有些元件在两类中都能找到。将嗜热四膜虫snRNA基因的启动子结构与其他生物的snRNA基因启动子结构进行比较，发现与植物snRNA基因有几个相似之处。这些相似之处包括整体启动子结构以及特定的序列元件。嗜热四膜虫一些snRNA基因3'侧翼区域的结构组织在其他生物中未观察到。结合其在snRNA 3'末端形成中可能发挥的作用对这一发现进行了讨论。
