STRUCT CHAR OF PROTEIN NUCLEIC ACID COMPLEXES IN NUCLEAR IMPORT

蛋白质和核酸的核进口是许多 细胞过程和细胞与病原体的相互作用。一些细菌和 病毒编码的特殊蛋白质可以运输基因组、DNA和RNA 入侵病原体的分子进入宿主细胞核。其中之一 这就是农杆菌的病毒E2蛋白。农杆菌引起了 肿瘤在许多植物物种上的生长是由一种 细菌转导DNA(T-DNA)的单链拷贝。 植物细胞核。仅病毒E2型似乎就足以运输 T-DNA进入宿主细胞核。因为T-DNA不是序列 具体地说，任何单链DNA和病毒E2之间的复合体都能胜任 活动性核导入L M 13单链DNA和病毒E 2孵育并检测 在STEM里。冷冻干燥和阴性染色的样本都是 准备好了。分析了相当坚硬的均匀长丝，包括 质量/长度、径向密度分布分析和建模以适应 观察染色数据。一个中空的电话线状线圈模型，12.6 直径为N，螺旋节距为4.4 NRN，大约 每二十个碱基中就有一个Vire2，符合所有数据。烟草花叶病毒运动蛋白 不是TMV病毒粒子的一部分，但对ftwisport到 主持人。蛋白质和烟草花叶病毒RNA的复合体在 但蛋白质/RNA比值太低。进一步的工作是 计划的

Nuclear import of proteins and nucleic acids is central to many cellular processes and cell-pathogen interactions. Some bacteria and viruses encode specialized proteins that Mansport genomic, DNA and RNA molecules of the invading pathogen into the host cell nucleus. One of these is the VirE2 protein of Agrobacterium. Agrobactenwn elicits neoplastic growths on many plant species by taiisporting a single-stranded copy of the bacterial tranderred DNA (T-DNA) into the. plant cell nucleus. VirE2 alone appears to be sufficient to transport T-DNA into the host cell nucleus. Since the T-DNA is not sequence specific, the complex between any ssDNA and VirE2 is competent for active nuclear imporL M 13 ssDNA and VirE2 were incubated and examined in the STEM. Both freeze-dried and negatively stained specimens were prepared. The rather rigid uniform filaments were analyzed, including mass/length, radial density profile analyses, and modeling to fit the observed stained data. A model of a hollow phone-cord like coil, 12.6 nin in diameter, with a helical pitch of 4.4 nrn, and approximately one VirE2 per twenty bases, fits all the data. TMV movement protein is not part of the TMV virion but is reponsible for the ftwisport into the host. Complexes of the protein and the TMV RNA were examined in the STEK but the protein/RNA ratio was too low. Further work is planned