Sashihara N, Kudo T, Horikoshi K
J Bacteriol. 1984 May;158(2):503-6. doi: 10.1128/jb.158.2.503-506.1984.
The genes for cellulases of alkalophilic Bacillus sp. strain N-4 were cloned in Escherichia coli with pBR322. Plasmids pNK1 and pNK2 were isolated from the transformants producing carboxymethyl cellulase, and the carboxymethyl cellulase genes cloned were in 2.0- and 2.8-kilobase-pair HindIII fragments, respectively. On the DNA level, the pNK1 fragment had a different restriction map from that of the pNK2 fragment, but the genomic hybridization experiments showed partial homology among these fragments. A total of 74 and 34% of the enzyme activities were observed in the periplasmic space of E. coli carrying the plasmids pNK1 and pNK2 , respectively. The carboxymethyl cellulase thus produced had broad pH activity curves (pH of 5 to 10.9) and was stable up to 75 degrees C.
嗜碱芽孢杆菌N-4菌株的纤维素酶基因用pBR322在大肠杆菌中进行了克隆。从产生羧甲基纤维素酶的转化体中分离出质粒pNK1和pNK2，克隆的羧甲基纤维素酶基因分别位于2.0千碱基对和2.8千碱基对的HindIII片段中。在DNA水平上，pNK1片段的限制性图谱与pNK2片段不同，但基因组杂交实验表明这些片段之间存在部分同源性。分别在携带质粒pNK1和pNK2的大肠杆菌周质空间中观察到74%和34%的酶活性。由此产生的羧甲基纤维素酶具有较宽的pH活性曲线（pH为5至10.9），并且在高达75摄氏度时稳定。
