Cloning, Expression and Deletion of Ademosine Deaminase Gene in Escherica coli
大肠杆菌腺苷脱氨酶基因的克隆、表达与缺失

Based on the principles of metabolic engineering, a new pathway of transforming adenosine to ATP is attempted to be built in the nucleotides metabolism of %E.coli %. Deletion of adenosine deaminase gene ( %add %) is to be needed. The %add % gene from %E.coli % MC4100 was cloned by constructing gene library and expressed through constructing two plasmids pBD1 adn pBD2. In order to get the %add %-defective strain, a 5 ^2kb DNA sequence including fragmental %add % gene and marker gene %Km +r % was made and transferred into JM83, MC4100 and BL21(DE3). The genetic stability and DNA hybridization experiment proved that two %add %-defective strain J1 and J2 come from JM83 were found. The enzyme assays indicated that strain J1 lost the adenosine deaminase activity and pBD1/JM83 showed higher adenosine deaminase activity than pUC18/JM83.