Barouki R, Smith H O
J Bacteriol. 1985 Aug;163(2):629-34. doi: 10.1128/jb.163.2.629-634.1985.
Radiolabeled donor DNA is efficiently taken up into competent H. influenzae Rd rec-2 mutant cells but does not undergo the rapid degradation observed in wild-type cells. Furthermore, donor label is not recovered in the chromosome even after 1 h. The donor DNA appears to remain in a protected state in a compartment that can be separated from the rest of the cell. We interpret this as a failure of the donor DNA to be translocated out of the transformasome. In contrast, rec-1 cells translocate labeled donor DNA normally. The donor label accumulates in the recipient chromosome, but, as expected for cells with a recombination defect, there is no preferential localization of the label in sites homologous to the donor DNA. In addition, we have observed two enzymatic activities that act on transformasome-associated DNA of rec-2 cells, an endonuclease which may play a role in the translocation of closed circular DNA and a phosphatase.
放射性标记的供体DNA能有效地被感受态流感嗜血杆菌Rd rec - 2突变体细胞摄取，但不会像在野生型细胞中那样迅速降解。此外，即使经过1小时，供体标记也不会在染色体中恢复。供体DNA似乎在一个可与细胞其他部分分离的区室中处于受保护状态。我们将此解释为供体DNA未能从转化体中转运出来。相比之下，rec - 1细胞能正常转运标记的供体DNA。供体标记积累在受体染色体中，但正如具有重组缺陷的细胞所预期的那样，标记在与供体DNA同源的位点没有优先定位。此外，我们还观察到两种作用于rec - 2细胞转化体相关DNA的酶活性，一种可能在闭环DNA转运中起作用的内切核酸酶和一种磷酸酶。
