Tong J, Wetmur J G
Department of Microbiology, Mount Sinai School of Medicine, New York 10029, USA.
J Bacteriol. 1996 May;178(9):2695-700. doi: 10.1128/jb.178.9.2695-2700.1996.
The ruvB genes of the highly divergent thermophilic eubacteria Thermus thermophilus and Thermotoga maritima were cloned, sequenced, and expressed in Escherichia coli. Both thermostable RuvB proteins were purified to homogeneity. Like E. coli RuvB protein, both purified thermostable RuvB proteins showed strong double-stranded DNA-dependent ATPase activity at their temperature optima (> or = 70 degrees C). In the absence of ATP, T. thermophilus RuvB protein bound to linear double-stranded DNA with a preference for the ends. Addition of ATP or gamma-S-ATP destabilized the T. thermophilus RuvB-DNA complexes. Both thermostable RuvB proteins displayed helicase activity on supercoiled DNA. Expression of thermostable T. thermophilus RuvB protein in the E. coli ruvB recG mutant strain N3395 partially complemented the UV-sensitive phenotype, suggesting that T. thermophilus RuvB protein has a function similar to that of E. coli RuvB in vivo.
克隆、测序了高度分化的嗜热真细菌嗜热栖热菌（Thermus thermophilus）和海栖热袍菌（Thermotoga maritima）的ruvB基因，并在大肠杆菌中进行了表达。两种耐热的RuvB蛋白均被纯化至同质。与大肠杆菌RuvB蛋白一样，两种纯化的耐热RuvB蛋白在其最适温度（≥70℃）下均表现出很强的双链DNA依赖性ATP酶活性。在没有ATP的情况下，嗜热栖热菌RuvB蛋白与线性双链DNA结合，偏好于末端。添加ATP或γ-S-ATP会使嗜热栖热菌RuvB-DNA复合物不稳定。两种耐热RuvB蛋白在超螺旋DNA上均显示解旋酶活性。耐热的嗜热栖热菌RuvB蛋白在大肠杆菌ruvB recG突变株N3395中的表达部分互补了对紫外线敏感的表型，表明嗜热栖热菌RuvB蛋白在体内具有与大肠杆菌RuvB类似的功能。
