曼氏血吸虫28S rRNA基因中一个54个核苷酸间隙区域的特征分析

Characterization of a 54-nucleotide gap region in the 28S rRNA gene of Schistosoma mansoni.

作者信息

van Keulen H, Mertz P M, LoVerde P T, Shi H, Rekosh D M

机构信息

Department of Microbiology, State University of New York, Buffalo 14214.

出版信息

Mol Biochem Parasitol. 1991 Apr;45(2):205-14. doi: 10.1016/0166-6851(91)90087-m.

DOI:10.1016/0166-6851(91)90087-m

PMID:2038356

Abstract

We have analyzed 572 bp in the 28S rDNA of the human blood fluke Schistosoma mansoni which correspond to expansion segment 5 of domain IV as defined by Clark et al. for the Xenopus laevis 28S rRNA. S1 nuclease mapping and primer extension analysis comparing this region with the mature 28S rRNA indicate that there are 54 nucleotides present in the 28S rDNA which are absent from the mature rRNA. This defines a gap that creates two 28S rRNA subunits (28S alpha and 28S beta). Comparison of the S. mansoni sequence with rDNAs of other organisms which contain gaps in their 28S rRNA shows that the overall features are conserved except that the S. mansoni gap is less A + T-rich. The conserved features include: (1) the location of the gap within the 28S rRNA; (2) the predicted secondary structure of the gap, containing a stem-loop with a UAAU sequence within the loop; and (3) a conserved CGAAAGGG on the 3' side of the gap.

摘要

我们分析了曼氏血吸虫28S rDNA中572个碱基对，这些碱基对对应于Clark等人针对非洲爪蟾28S rRNA所定义的结构域IV的扩展片段5。通过S1核酸酶图谱分析以及将该区域与成熟28S rRNA进行引物延伸分析表明，28S rDNA中存在54个核苷酸，而成熟rRNA中不存在这些核苷酸。这确定了一个缺口，该缺口形成了两个28S rRNA亚基（28Sα和28Sβ）。将曼氏血吸虫的序列与其他在28S rRNA中存在缺口的生物的rDNA进行比较，结果表明，除了曼氏血吸虫的缺口富含A + T的程度较低外，总体特征是保守的。保守特征包括：（1）缺口在28S rRNA中的位置；（2）缺口的预测二级结构，在环内包含一个带有UAAU序列的茎环；（3）缺口3'侧的保守序列CGAAAGGG。