PALINDROMIC UNITS ARE PART OF A NEW BACTERIAL INTERSPERSED MOSAIC ELEMENT (BIME)
PALINDROMIC UNITS ARE PART OF A NEW BACTERIAL INTERSPERSED MOSAIC ELEMENT (BIME)
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DOI：
10.1093/nar/19.7.1375
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发表时间：
1991-04-11
影响因子：
14.9
通讯作者：
HOFNUNG, M
中科院分区：
文献类型：
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作者：
GILSON, E;SAURIN, W;HOFNUNG, M
回文单位（Palindromic Units， PU或REP）是指大肠杆菌和其他肠杆菌科细菌基因组中高度重复的40个核苷酸的DNA序列。Pu以多达6例的集群出现，总是定位于外基因区域。通过将已知含有PU区域的DNA序列分类为不同的类别，我们首次发现，除了PU本身，每个PU簇还包含许多其他保守的序列基序。七个这样的基序被确定为目前的PU区域列表。值得注意的是，每个PU簇完全由PU和这些其他序列基序的马赛克组合组成。我们通过杂交实验直接证明，这些基序之一（称为L）确实存在于大肠杆菌染色体上的大量拷贝中，并且其分布遵循与PU序列本身相同的物种特异性。我们认为PU簇中基序组合的马赛克模式揭示了一种新的细菌遗传元件，我们建议将其称为BIME （bacterial Interspersed mosaic element）。大肠杆菌基因组包含约500个BIME。
Palindromic Units (PU or REP) were defined as DNA sequences of 40 nucleotides highly repeated on the genome of Escherichia coli and other Enterobacteriaceae. Pu are found in clusters of up to six occurrences always localized in extragenic regions. By sorting the DNA sequences of the known PU containing regions into different classes, we show here for the first time that, besides the PU themselves, each PU clusters contains a number of other conserved sequence motifs. Seven such motifs were identified with the present list of PU regions. Remarkably, each PU cluster is exclusively composed of a mosaic combination of PU and of these other sequence motifs. We demonstrate directly by hybridization experiments that one of these motifs (called L) is indeed present at a large number of copies on the Escherichia coli chromosome and that its distribution follows the same species specificity as PU sequences themselves. We propose that the mosaic pattern of motif combination in PU clusters reveals a new type of bacterial genetic element which we propose to call BIME for Bacterial Interspersed Mosaic Element. The Escherichia coli genome contains about 500 BIME.