Ogura T, Hiraga S
Cell. 1983 Feb;32(2):351-60. doi: 10.1016/0092-8674(83)90454-3.
Plasmids that replicate using the replication origin (oriC) of the E. coli chromosome are not stably inherited through cell division, but can be stabilized by joining with a particular segment of F plasmid that presumably provides the partition function. The segment necessary for stabilization has been located within a 3.0 kb segment outside of the region essential for autonomous replication of the F plasmid. This segment contains three functionally distinct regions: two of them (designated sopA and sopB) specify gene products that act in trans, whereas the third region (sopC) acts in cis. All three functions seem to be essential for normal partition of the plasmid into daughter cells during cell division. The cis-acting region also specifies plasmid incompatibility.
利用大肠杆菌染色体复制起点（oriC）进行复制的质粒在细胞分裂过程中不能稳定遗传，但通过与F质粒的特定片段连接可以实现稳定遗传，该片段可能提供了分配功能。实现稳定遗传所必需的片段位于F质粒自主复制所需区域之外的一个3.0 kb片段内。该片段包含三个功能不同的区域：其中两个区域（分别命名为sopA和sopB）编码反式作用的基因产物，而第三个区域（sopC）则顺式作用。所有这三种功能对于质粒在细胞分裂过程中正常分配到子细胞中似乎都是必不可少的。顺式作用区域还决定了质粒的不相容性。
