Hirooka T, Kado C I
J Bacteriol. 1986 Oct;168(1):237-43. doi: 10.1128/jb.168.1.237-243.1986.
The right boundary of the virulence (Vir) region of the nopaline plasmid pTiC58 of Agrobacterium tumefaciens was determined by transposon insertion, cartridge emplacement, and deletion mutagenesis. Genetic complementation with mutant and wild-type alleles led to the identification of the virE locus at the right boundary, which was located about 6 kilobases from the left border of the segment of DNA that is transferred into the plant genome. virE is 2.0 kilobases long and encodes at least one protein of 69 kilodaltons. Various mutations in virE resulted in different truncated lengths of the 69-kilodalton protein. As this protein was increasingly truncated from the carboxy terminus, the host range of A. tumefaciens and the frequency of tumor formation diminished concomitantly. Thus, as one of its functions, the 69-kilodalton protein of virE is probably involved in some aspect of the host range specificity of A. tumefaciens and in infection efficiency.
通过转座子插入、盒式插入和缺失诱变确定了根癌土壤杆菌胭脂碱型质粒pTiC58毒性（Vir）区域的右边界。用突变体和野生型等位基因进行遗传互补，从而在右边界鉴定出了virE基因座，该基因座位于转入植物基因组的DNA片段左边界约6千碱基处。virE长2.0千碱基，编码至少一种69千道尔顿的蛋白质。virE中的各种突变导致69千道尔顿蛋白质的截短长度不同。随着该蛋白质从羧基末端越来越多地被截短，根癌土壤杆菌的宿主范围和肿瘤形成频率也随之降低。因此，作为其功能之一，virE的69千道尔顿蛋白质可能在根癌土壤杆菌宿主范围特异性的某些方面以及感染效率中发挥作用。
