Xia M, Zhu Y, Cao X, You L, Chen Z
National Laboratory of Protein Engineering, Peking University, Beijing, People's Republic of China.
FEMS Microbiol Lett. 1995 Apr 1;127(3):235-42. doi: 10.1111/j.1574-6968.1995.tb07479.x.
Using a genomic subtraction technique, we cloned a DNA sequence that is present in wild-type Escherichia coli strain CSH4 but is missing in a presumptive proline dehydrogenase deletion mutant RM2. Experimental evidence indicated that the cloned fragment codes for proline dehydrogenase (EC 1.5.99.8) since RM2 cells transformed with a plasmid containing this sequence was able to survive on minimal medium supplemented with proline as the sole nitrogen and carbon sources. The cloned DNA fragment has an open reading frame of 3942 bp and encodes a protein of 1313 amino acids with a calculated Mr of 143,808. The deduced amino acid sequence of the E. coli proline dehydrogenase has an 84.9% homology to the previously reported Salmonella typhimurium putA gene but it is 111 amino acids longer at the C-terminal than the latter.
利用基因组消减技术，我们克隆了一个DNA序列，该序列存在于野生型大肠杆菌CSH4菌株中，但在假定的脯氨酸脱氢酶缺失突变体RM2中缺失。实验证据表明，克隆的片段编码脯氨酸脱氢酶（EC 1.5.99.8），因为用含有该序列的质粒转化的RM2细胞能够在以脯氨酸作为唯一氮源和碳源的基本培养基上存活。克隆的DNA片段有一个3942 bp的开放阅读框，编码一个1313个氨基酸的蛋白质，计算得出的分子量为143,808。大肠杆菌脯氨酸脱氢酶的推导氨基酸序列与先前报道的鼠伤寒沙门氏菌putA基因有84.9%的同源性，但在C端比后者长111个氨基酸。
