Ramotar D, Popoff S C, Demple B
Laboratory of Toxicology, Harvard School of Public Health, Boston, Massachusetts 02115.
Mol Microbiol. 1991 Jan;5(1):149-55. doi: 10.1111/j.1365-2958.1991.tb01835.x.
The Saccharomyces cerevisiae APN1 gene encoding an AP endonuclease/3'-diesterase was engineered in vitro for expression in Escherichia coli. The expression vector directs the synthesis in E. coli of a Mr 40,500 protein that reacts with anti-Apn1 antibodies and has the DNA-repair activities characteristic of Apn1 isolated from yeast. A band corresponding to Apn1 was observed in DNA repair activity gels only with extracts of E. coli harbouring the APN1 expression plasmid. Expression of Apn1 conferred resistance to oxidants and alkylating agents in E. coli lacking exonuclease III and endonuclease IV. For H2O2 damage, this rescue effect was correlated with the repair of oxidative lesions in the bacterial chromosome by the Apn1 protein. Thus, Apn1 can function in bacteria in a manner similar to its proposed multiple functions in yeast.
编码一种AP核酸内切酶/3'-二酯酶的酿酒酵母APN1基因在体外进行改造，以便在大肠杆菌中表达。该表达载体指导大肠杆菌合成一种分子量为40,500的蛋白质，该蛋白质能与抗Apn1抗体发生反应，并具有从酵母中分离出的Apn1的DNA修复活性特征。仅在携带APN1表达质粒的大肠杆菌提取物的DNA修复活性凝胶中观察到一条与Apn1相对应的条带。Apn1的表达赋予缺乏外切核酸酶III和内切核酸酶IV的大肠杆菌对氧化剂和烷化剂的抗性。对于H2O2损伤，这种拯救作用与Apn1蛋白对细菌染色体中氧化损伤的修复相关。因此，Apn1在细菌中的功能方式与其在酵母中所推测的多种功能相似。
