非洲锥虫微小环中的序列组织由18个碱基对的反向重复序列定义。

Sequence organization in African trypanosome minicircles is defined by 18 base pair inverted repeats.

作者信息

Jasmer D P, Stuart K

出版信息

Mol Biochem Parasitol. 1986 Mar;18(3):321-31. doi: 10.1016/0166-6851(86)90089-7.

Abstract

We have found that minicircles of African trypanosomes contain 18 base pair sequences that occur as 3 or 4 pairs of imperfect inverted repeats. The 18 base pair sequence is polar; one half is almost perfectly conserved, while the other half has a more variable sequence. The distribution of the 18 base pair sequences in minicircles defines two classes of sequences ('A' and 'B' segments) that have distinct characteristics. 'A' segments vary considerably in length and contain about 10% more G+C than 'B' segments which are all about 100 base pairs long. The 18 base pair sequences are absent from minicircles of other kinetoplastids. Thus, 'B' segments along with their terminal 18 base pair sequences superficially resemble insertion sequences. Minicircles of African trypanosomes therefore conserve their organization but have only limited nucleotide sequence homology.

摘要

我们发现，非洲锥虫的微小环含有18个碱基对的序列，这些序列以3或4对不完全反向重复的形式出现。18个碱基对的序列具有极性；一半几乎完全保守，而另一半的序列则更具变异性。微小环中18个碱基对序列的分布定义了两类具有不同特征的序列（“A”和“B”片段）。“A”片段的长度差异很大，其G+C含量比均约为100个碱基对长的“B”片段多10%左右。其他动基体的微小环中不存在18个碱基对的序列。因此，“B”片段及其末端的18个碱基对序列表面上类似于插入序列。非洲锥虫的微小环因此保留了它们的组织，但只有有限的核苷酸序列同源性。