Tenke E, Bánfalvi G
1st Institute of Biochemistry, Semmelweis University Medical School, Budapest, Hungary.
Acta Biochim Biophys Hung. 1990;25(1-2):101-9.
The inactivation of rec BC (D) DNase upon chromatography on DEAE-cellulose was observed. Simultaneously DNA-stimulated ATPases (I and II) and DNase activities on single- and double-stranded DNA substrates were measured in Escherichia coli rec+ and rec- cell extracts. Normal levels of ATPase I and II were detected in rec+ cells. Rec A- cells were lacking DNA dependent ATPase I, while rec B single and rec BC double mutants were defective in DNA dependent ATPase II, the second major enzyme of this type. Rec B and C mutations did not change DNase activities. Rec A mutation significantly increased DNase activity on linear single-stranded substrate.
观察到rec BC (D) 脱氧核糖核酸酶在DEAE - 纤维素柱层析上的失活现象。同时，在大肠杆菌rec⁺和rec⁻细胞提取物中，测定了DNA刺激的ATP酶（I和II）以及单链和双链DNA底物上的脱氧核糖核酸酶活性。在rec⁺细胞中检测到正常水平的ATP酶I和II。Rec A⁻细胞缺乏DNA依赖性ATP酶I，而rec B单突变体和rec BC双突变体在DNA依赖性ATP酶II方面存在缺陷，该酶是此类的第二种主要酶。Rec B和C突变并未改变脱氧核糖核酸酶活性。Rec A突变显著增加了线性单链底物上的脱氧核糖核酸酶活性。
