布氏锥虫多聚泛素基因的等位基因多态性

Allelic polymorphism of the Trypanosoma brucei polyubiquitin gene.

作者信息

Wong S, Elgort M G, Gottesdiener K, Campbell D A

机构信息

Department of Microbiology and Immunology, University of California, Los Angeles 90024.

出版信息

Mol Biochem Parasitol. 1992 Oct;55(1-2):187-95. doi: 10.1016/0166-6851(92)90139-b.

DOI:10.1016/0166-6851(92)90139-b

PMID:1331786

Abstract

We have characterized a second T. brucei polyubiquitin gene (UbB) that is highly similar in the coding and flanking regions to a previously described T. brucei polyubiquitin gene (UbA). However, UbB differs from UbA in 2 respects: (1) the predicted carboxy-terminal amino acid of UbB is methionine, as opposed to leucine in UbA, and (2) UbB contains approximately 13 ubiquitin repeats, as opposed to approximately 30 repeats in UbA. In Southern blots of intact T. brucei DNA separated by pulsed field gel electrophoresis, the polyubiquitin sequences have been shown to reside on band 19, which may contain 3 chromosomes. Three experiments that target a neomycin-resistance gene to the polyubiquitin locus demonstrate a one-to-one ratio of polyubiquitin 3-flanking sequences, which suggests that UbA and UbB are alleles rather than duplications. Four additional strains of T. brucei and one strain of T. equiperdum show variation in their polyubiquitin gene size, suggesting that this is a common polymorphism.

摘要

我们鉴定了第二个布氏锥虫多聚泛素基因（UbB），其编码区和侧翼区域与先前描述的布氏锥虫多聚泛素基因（UbA）高度相似。然而，UbB在两个方面与UbA不同：（1）UbB预测的羧基末端氨基酸是甲硫氨酸，而UbA是亮氨酸；（2）UbB含有约13个泛素重复序列，而UbA约有30个重复序列。在通过脉冲场凝胶电泳分离的完整布氏锥虫DNA的Southern印迹中，多聚泛素序列已显示位于第19条带，该条带可能包含3条染色体。将新霉素抗性基因靶向多聚泛素基因座的三个实验表明，多聚泛素3'侧翼序列的比例为一对一，这表明UbA和UbB是等位基因而非重复基因。另外四个布氏锥虫菌株和一个马媾疫锥虫菌株的多聚泛素基因大小存在差异，表明这是一种常见的多态性。