Naito T, Kusano K, Kobayashi I
Department of Molecular Biology, University of Tokyo, Japan.
Science. 1995 Feb 10;267(5199):897-9. doi: 10.1126/science.7846533.
Plasmids carrying gene pairs encoding type II DNA restriction endonucleases and their cognate modification enzymes were shown to have increased stability in Escherichia coli. The descendants of cells that had lost these genes appeared unable to modify a sufficient number of recognition sites in their chromosomes to protect them from lethal attack by the remaining restriction enzyme molecules. The capacity of these genes to act as a selfish symbiont is likely to have contributed to the evolution of restriction-modification gene pairs.
携带编码II型DNA限制性内切酶及其同源修饰酶基因对的质粒在大肠杆菌中表现出更高的稳定性。丢失这些基因的细胞后代似乎无法修饰其染色体中足够数量的识别位点，从而无法保护它们免受剩余限制性酶分子的致命攻击。这些基因作为自私共生体的能力可能有助于限制-修饰基因对的进化。
