耐辐射奇球菌recA基因的克隆、表达及其对recA缺损大肠杆菌辐射抗性的影响

将耐辐射奇球菌(Deinococcus radiodurans)recA基因克隆到表达质粒pET15b中，并在Escherichia coli HMS中高效表达了可溶性的RecA重组蛋白。同时将recA基因通过穿梭质粒pRADZ3导入recA缺损E.coli TG2细胞中，Western印迹实验显示RecA蛋白能够在不需要诱导剂IPTG的条件下稳定表达。辐射抗性实验表明，D.radiodurans的recA基因在E.coli细胞中的表达能够完全补偿recA缺损E.coli辐射抗性能力。

Cloning,Expression of recA Gene from Deinococcus radiodurans and the Effect of Radioresistance of recA Defective Escherichia coli

The recA gene of D. radiodurans was cloned into expression vector pET15b and a recombinant fusion RecA protein was overexpressed in E. coli HMS (DE3) by IPTG induction. On the other hand, we have succeeded in the normal expression of the cloned recA gene of D. radiodurans in E. coli via a shuttle plasmid pRADZ3 under the control of GroES promoter without induction of IPTG. The expression of recA gene of D. radiodurans in E. coli TG2 was able to completely complement its defective radioresistance, caused by the intrinsic recA deficiency, following exposure to ionizing radiation.