Hashimoto-Gotoh T, Timmis K N
Cell. 1981 Jan;23(1):229-38. doi: 10.1016/0092-8674(81)90287-7.
The incompatibility properties of Col E1-like plasmids have been examined in Rec+ and RecA- bacteria. Two Col E1- (or two pMB1-) derivative plasmids coreplicated in the same clone for many cell doublings, irrespective of the rec genotype of host bacteria. Their kinetics of segregation were found to be consistent with models that assume a random choice of template molecule for each plasmid replication event, but with models based on a single (master) template molecule per cell. In contrast, minimal coreplication of a Col E1- and a pMB1-derivative plasmid occurred, with the latter type rapidly excluding the former. We suggest here that the pMB1 derivatives, pMB9 and pBR322, are less sensitive than Col E1 derivatives to the putative inhibitor that regulates plasmid replication, due to base sequence differences in their target for the inhibitor, and consider one mechanism whereby the duplication of Col E1-like plasmids might be regulated.
已在Rec⁺和RecA⁻细菌中研究了Col E1样质粒的不相容特性。两个Col E1（或两个pMB1）衍生质粒在同一克隆中共同复制了许多细胞世代，与宿主细菌的rec基因型无关。发现它们的分离动力学与假设每个质粒复制事件随机选择模板分子的模型一致，但与基于每个细胞单个（主）模板分子的模型一致。相比之下，Col E1和pMB1衍生质粒的共复制极少发生，后一种类型会迅速排除前一种类型。我们在此提出，由于其抑制剂靶标的碱基序列差异，pMB1衍生物pMB9和pBR322比Col E1衍生物对调节质粒复制的假定抑制剂更不敏感，并考虑了一种调节Col E1样质粒复制的机制。
