Citovsky V, Zupan J, Warnick D, Zambryski P
Department of Plant Biology, University of California, Berkeley 94720.
Science. 1992 Jun 26;256(5065):1802-5. doi: 10.1126/science.1615325.
The Agrobacterium single-stranded DNA (ssDNA) intermediate T-strand is likely transferred to the plant cell nucleus as a complex with a single VirD2 molecule at its 5' end and multiple VirE2 molecules along its length. VirD2 contains a nuclear localization signal (NLS); however, because the T-strand is principally coated with VirE2 molecules, VirE2 also might assist in nuclear uptake. Indeed, VirE2 fused to a reporter protein localizes to plant cell nuclei, a process mediated by two amino acid sequences with homology to the bipartite NLS of Xenopus nucleoplasmin. Moreover, tumorigenicity of an avirulent virE2 mutant is restored when inoculated on transgenic plants expressing VirE2, supporting in planta function of VirE2.
农杆菌单链DNA（ssDNA）中间体T链可能作为一种复合物转移到植物细胞核中，该复合物在其5'端与单个VirD2分子结合，沿其长度与多个VirE2分子结合。VirD2含有一个核定位信号（NLS）；然而，由于T链主要被VirE2分子覆盖，VirE2也可能有助于核摄取。事实上，与报告蛋白融合的VirE2定位于植物细胞核，这一过程由两个与非洲爪蟾核纤层蛋白的双分型NLS具有同源性的氨基酸序列介导。此外，当无毒的virE2突变体接种在表达VirE2的转基因植物上时，其致瘤性得以恢复，这支持了VirE2在植物体内的功能。
