Genes involved in production of plasmidlike forms by a Bacteroides conjugal chromosomal element share amino acid homology with two-component regulatory systems.
Genes involved in production of plasmidlike forms by a Bacteroides conjugal chromosomal element share amino acid homology with two-component regulatory systems.
复制标题
拟杆菌共轭染色体元件产生质粒样形式所涉及的基因与双组分调节系统具有氨基酸同源性。
DOI：
10.1128/jb.174.9.2935-2942.1992
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发表时间：
1992
影响因子：
3.2
通讯作者：
Salyers,AA
中科院分区：
文献类型：
--
作者：
Stevens,AM;Sanders,JM;Shoemaker,NB;Salyers,AA
Many human colonic Bacteroides strains carry large (greater than 70-kbp) self-transmissible chromosomal tetracycline resistance (Tcr) elements. These Tcr elements can also mediate the excision and circularization of discrete nonadjacent segments of chromosomal DNA which are designated NBUs (nonreplicating Bacteroides units). We have localized a 6.5-kbp segment of Tcr element DNA that mediates NBU excision and circularization. Analysis of the DNA sequence of this region indicated that it contained three open reading frames, all transcribed in the same direction. The first gene was the Tcr gene, tetQ. The second two open reading frames exhibited amino acid similarity to known two-component regulatory systems. Complementation and gene fusion data supported the hypothesis that the three genes were organized in an operon. Transcription from the tetQ promoter region was inducible by tetracycline, as might be expected from the previous finding that NBU excision was detectable only in cells preexposed to tetracycline. The 6.5-kbp region appeared to be essential not only for NBU excision but also for self-transfer of the elements, another activity that is enhanced by preexposure to tetracycline. Accordingly, the two genes downstream of tetQ have been designated rteA and rteB (regulation of Tcr elements).
