RIBONUCLEASE AND ITS INHIBITOR FROM BACILLUS AMYLOLIQUENFACIENS

芽孢杆菌的胞外核糖核酸酶Barnase Amyloliquefaciens及其胞内抑制物Barstar被用作 蛋白质-蛋白质折叠研究的模型系统 互动。Barnase是核糖核酸酶的同源基团之一 存在于原核生物和真核生物中。 重组DNA技术正在应用于该项目，有三个 主要目标：1)促进生产，2)审查结构和 基因的控制序列和3)量身定做 对序列进行修改，以测试蛋白质折叠理论。 完整的barnase基因在大肠杆菌或 枯草杆菌。利用基本组氨酸-102的定向突变 基因在这两种生物中都有表达，但突变产物不表达 处理正确。已经设计了一个载体，基于启动子和 Pho-A基因的信号序列，它允许轻松地生产 该突变(突变)酶产量高(16-20 mg/升。 Barstar基因也在大肠杆菌中被克隆，在那里它被表达为 一种特定的谷氨酸酶的抑制剂。

Two proteins, barnase, the extracellular ribonuclease of Bacillus amyloliquefaciens, and barstar, its intracellular inhibitor, are used as a model system for the study of protein folding a protein-protein interactions. Barnase is one of an homologous group of ribonucleases occurring in both prokaryotes and eukaryotes. Recombinant DNA techniques are being applied to the project with three major aims; 1) to facilitate production, 2) to examine the structural and control sequences of the genes and 3) to tailor specifically designed modifications in the sequences to test theories of protein folding. The complete barnase gene is lethal when reassembled in either E. coli or B. subtilis. With directed mutation of the essential histidine-102 the gene is expressed in both organisms, but the mutant products are not correctly processed. A vector has been devised, based on the promoter and signal sequence of the of the Pho-A gene, which allows facile production of the muture (mutant) enzyme in high yield (16-20 mg/liter. The barstar gene has also been cloned in E. coli, where it is expressed as a specific inhibitor of barnase.