渗透压调节基因proBA的融合表达对大肠杆菌耐高渗胁迫能力的影响

枯草芽孢杆菌 9315 1的渗透压调节基因proB和proA以重叠基因的方式组织 ,但是表达两个单独的蛋白质ProB和ProA。通过引物设计 ,在抗脯氨酸反馈抑制耐盐突变菌株 9315 1 14的proBA基因重叠区引入一个限制性酶切位点 ,分别扩增出proB和proA基因 ,并构建融合的proBA基因。SDS PAGE分析显示有一条新的分子质量约为85kD的蛋白带出现。相对于表达未融合的proB和proA ,proBA融合基因的表达明显提高了宿主菌大肠杆菌JM83胞内游离脯氨酸含量和其耐高渗胁迫能力

Construction of fused osmoregulation proBA gene from a salt-tolerant mutant of Bacillus subtilis and its influence on the osmotolerance of Escherichia coli

The osmoregulation proB and proA genes from Bacillus subtilis 93151 are overlapping genes, which encode two proteins ProB and ProA. A restriction enzyme site was inserted in the overlapping region of proB and proA genes from a salt-tolerant mutant of B. subtilis 93151, and a fusion gene was constructed by cloning proB and proA genes respectively. SDS-PAGE analysis showed that a novel protein with molecular mass of 85 kD was observed. When expressed in E.coli, enhanced intracellular concentrations of free proline and osmotolerance of the strain carrying the fusion gene were observed, compared with the control host cell harbouring a plasmid encoding the separate ProB and ProA.