Delineation of the regulatory region sequences of Agrobacterium tumefaciens virB operon.
Delineation of the regulatory region sequences of Agrobacterium tumefaciens virB operon.
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根癌农杆菌 virB 操纵子调控区序列的描绘。
DOI：
10.1093/nar/17.12.4541
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发表时间：
1989
影响因子：
14.9
通讯作者：
G. Pazour
中科院分区：
文献类型：
--
作者：
A. Das;G. Pazour
构建了VIRB-LacZ翻译融合系统，用于监测农杆菌VIRB操纵子的表达。融合基因的表达依赖于pTiA6Vira、Virg和植物因子乙酰丁香酮的存在。经BAL31酶切构建的缺失突变体分析表明，VIRB转录起始点上游的68个残基是其表达所必需的。位于-62和-61位的TT-CC替换导致VIRB表达减少7倍。VIRB上游区含有一个十四聚体序列dPuT/ATDCAATGHAAPy(D=A、G或T；H=A、C或T)，该序列在所有VIR基因的非转录区域中都是保守的。该序列相对于启动子区域序列的位置改变对VIRB的表达有很大的负面影响。
A virB-lacZ translational fusion was constructed to monitor expression of the Agrobacterium tumefaciens virB operon. Expression of the fusion gene was dependent on the presence of pTiA6 virA, virG, and a plant factor acetosyringone. Analysis of deletion mutants, constructed by exonuclease Bal31 digestion, showed that 68 residues upstream of the virB transcription initiation site was necessary for its expression. A TT----CC substitution at positions -62 and -61 led to a 7 fold reduction in virB expression. The virB upstream region contains a tetradecameric sequence, dPuT/ATDCAATGHAAPy (D = A, G or T; H = A, C or T), that is conserved in the non-transcribed regions of all vir genes. Alteration of the position of this sequence relative to the promoter region sequences had a drastic negative effect on virB expression.