CHARACTERIZATION OF THE VIRA LOCUS OF AGROBACTERIUM-TUMEFACIENS - A TRANSCRIPTIONAL REGULATOR AND HOST RANGE DETERMINANT
CHARACTERIZATION OF THE VIRA LOCUS OF AGROBACTERIUM-TUMEFACIENS - A TRANSCRIPTIONAL REGULATOR AND HOST RANGE DETERMINANT
复制标题
DOI：
10.1002/j.1460-2075.1987.tb04830.x
复制
发表时间：
1987-04-01
期刊：
影响因子：
11.4
通讯作者：
NESTER, EW
中科院分区：
文献类型：
--
作者：
LEROUX, B;YANOFSKY, MF;NESTER, EW
根癌农杆菌的毒力（vir）区介导质粒DNA（T-DNA）的限定片段转移到植物基因组中。vir基因由受伤的植物细胞产生的分子特异性诱导，并且这种诱导需要virA。我们已经确定了来自有限（pTiAg 162）和宽（pTiA 6）宿主范围肿瘤诱导（Ti）质粒的virA基因座的核苷酸序列，每个质粒编码92，000道尔顿的单一蛋白质。使用针对virA基因产物的抗体，我们已经将VirA蛋白定位于细菌内膜。VirA与至少四种细菌蛋白同源，这些蛋白在不同基因家族的转录调控中发挥作用。基于其在vir基因诱导中的作用、与转录调控因子的同源性和膜定位，我们提出VirA作为植物源诱导分子的环境传感器，并将此信息传递到vir基因表达水平。 pTiAg 162 virA基因座在指导vir基因诱导方面显示出无效，这表明这可能部分地导致该质粒赋予的窄宿主范围。
The virulence (vir) region of Agrobacterium tumefaciens mediates the transfer of a defined segment of plasmid DNA (the T-DNA) into the plant genome. The vir genes are specifically induced by molecules produced by wounded plant cells, and virA is required for this induction. We have determined the nucleotide sequence of virA loci from limited (pTiAg162) and wide (pTiA6) host range tumor-inducing (Ti) plasmids, each of which encodes a single protein of 92,000 daltons. Using antibody directed against the virA gene product, we have localized the VirA protein to the bacterial inner membrane. VirA is homologous to at least four bacterial proteins which play a role in the transcriptional regulation of diverse families of genes. Based on its role in vir gene induction, homology to transcriptional regulators and membrane localization, we propose that VirA acts as an environmental sensor of plant-derived inducer molecules and transmits this information to the level of vir gene expression. The pTiAg162 virA locus was shown to be ineffective at directing vir gene induction, suggesting that this may in part contribute to the narrow host range conferred by this plasmid.