Kooistra J, Haijema B J, Venema G
Department of Genetics, University of Groningen, Haren, The Netherlands.
Mol Microbiol. 1993 Mar;7(6):915-23. doi: 10.1111/j.1365-2958.1993.tb01182.x.
An Escherichia coli recBCD deletion mutant was transformed with plasmids containing the Bacillus subtilis add genes. The transformants had relatively high ATP-dependent exonuclease- and ATP-dependent helicase activities, and their viability, the ability to repair u.v.-damaged DNA and the recombination in conjugation were nearly completely restored. The B. subtilis Add enzyme did not show Chi-activity in phage lambda recombination. The individual B. subtilis Add proteins were not able to form an enzymatically active complex with the E. coli RecB,C,D proteins, and they could not complement the recB,C,D deficiency. Evidence is presented that only two subunits are involved in the B. subtilis ATP-dependent exonuclease. This is in contrast to E. coli in which the RecBCD enzyme consists of three subunits.
用含有枯草芽孢杆菌add基因的质粒转化大肠杆菌recBCD缺失突变体。转化体具有相对较高的ATP依赖性核酸外切酶活性和ATP依赖性解旋酶活性，其活力、修复紫外线损伤DNA的能力以及接合中的重组能力几乎完全恢复。枯草芽孢杆菌Add酶在噬菌体λ重组中不显示Chi活性。单个枯草芽孢杆菌Add蛋白不能与大肠杆菌RecB、C、D蛋白形成酶活性复合物，也不能弥补recB、C、D缺陷。有证据表明，枯草芽孢杆菌ATP依赖性核酸外切酶仅涉及两个亚基。这与由三个亚基组成RecBCD酶的大肠杆菌形成对比。
