THE 5'-LIMIT OF TRANSPOSITION AND UPSTREAM BARREN REGION OF A TRYPANOSOME VSG GENE - TANDEM-76 BASE-PAIR REPEATS FLANKING (TAA)90
THE 5'-LIMIT OF TRANSPOSITION AND UPSTREAM BARREN REGION OF A TRYPANOSOME VSG GENE - TANDEM-76 BASE-PAIR REPEATS FLANKING (TAA)90
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DOI：
10.1093/nar/12.6.2759
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发表时间：
1984-01-01
影响因子：
14.9
通讯作者：
BOOTHROYD, JC
中科院分区：
文献类型：
--
作者：
CAMPBELL, DA;VANBREE, MP;BOOTHROYD, JC
我们已经克隆并测序了布氏锥虫VSG基因上游的一部分区域。这种“表达连锁拷贝”是通过将沉默的基因的“基本拷贝”复制和转位到表达位点而产生的。比较两个基因座中转座片段5‘-端周围的序列表明，转座的5’-极限位于在基本复制基因座此位置发现的三个重复片段中的第一个(3‘-最)。这些高度保守的重复片段平均长度为76个碱基对，在表达位点转座片段的上游也发现了随机重复的片段。然而，在后一个位点中，它们更多(至少17个重复)，并且在一个重复的中间，它们被由(TAA)90组成的270个碱基对区中断。讨论了这些不寻常的序列在转座和VSG基因不连续转录模型中的可能作用。
We have cloned and sequenced a portion of the region upstream of an expressed VSG gene ofTrypanosoma brucei. This “expression-linked copy” arose through the duplication and transposition of a silent, “basic copy” of the gene to an expression site. Comparison of the sequences surrounding the 5′-end of the transposed segment in the two loci indicates the 5′-limit of transposition lies within the first (3′-most) of three repeated segments found at this position in the basic copy locus. These highly conserved repeat segments which average 76 base-pairs in length are also found tandemly repeated upstream of the transposed segment in the expression site. In this latter site, however, they are more numerous (at least 17 repeats) and they are interrupted, within the middle of one repeat, by a 270 base-pair region consisting of (TAA)90. The possible roles of these unusual sequences in transposition and in a model proposing discontinuous transcription of VSG genes are discussed