Schiestl R H, Zhu J, Petes T D
Department of Molecular and Cellular Toxicology, Harvard School of Public Health, Boston, Massachusetts 02115.
Mol Cell Biol. 1994 Jul;14(7):4493-500. doi: 10.1128/mcb.14.7.4493-4500.1994.
Restriction enzyme-mediated events (REM events; integration of transforming DNA catalyzed by in vivo action of a restriction enzyme) and illegitimate recombination events (IR events; integration of transforming DNA that shares no homology with the host genomic sequences) have been previously characterized in Saccharomyces cerevisiae. This study determines the effect of mutations in genes that are involved in homologous recombination and/or in the repair of double-stranded DNA breaks on these recombination events. Surprisingly, REM events are completely independent of the double-strand-break repair functions encoded by the RAD51, RAD52, and RAD57 genes but require the RAD50 gene product. IR events are under different genetic control than homologous integration events. In the rad50 mutant, homologous integration occurred at wild-type frequency, whereas the frequency of IR events was 20- to 100-fold reduced. Conversely, the rad52 mutant was grossly deficient in homologous integration (at least 1,000-fold reduced) but showed only a 2- to 8-fold reduction in IR frequency.
限制酶介导的事件（REM事件；由限制酶的体内作用催化的转化DNA整合）和非同源重组事件（IR事件；与宿主基因组序列无同源性的转化DNA整合）先前已在酿酒酵母中得到表征。本研究确定了参与同源重组和/或双链DNA断裂修复的基因突变对这些重组事件的影响。令人惊讶的是，REM事件完全独立于由RAD51、RAD52和RAD57基因编码的双链断裂修复功能，但需要RAD50基因产物。IR事件受与同源整合事件不同的遗传控制。在rad50突变体中，同源整合以野生型频率发生，而IR事件的频率降低了20至100倍。相反，rad52突变体在同源整合方面严重缺陷（至少降低了1000倍），但IR频率仅降低了2至8倍。
