Vanooteghem J C, Cornelis G R
Unité de Microbiologie, Université de Louvain, Brussels, Belgium.
J Bacteriol. 1990 Jul;172(7):3600-8. doi: 10.1128/jb.172.7.3600-3608.1990.
We sequenced the minimum replication region of the virulence plasmid pYVe439-80 from a serogroup O:9 Yersinia enterocolitica. This sequence is 68% homologous on a 1,873-nucleotide stretch to the sequence of the RepFIIA replicon of the resistance plasmid R100. The sequence contains two open reading frames, repA and repB, encoding proteins of 33,478 and 9,568 daltons, respectively. The amino acid sequences of the two proteins are 77 and 55% identical, respectively, to proteins RepA1 and RepA2 of the R100 replicon. Analysis of minicells transformed with a copy number mutant demonstrated that the replication region of pYVe439-80 directs the synthesis of a 33-kilodalton protein. Disruption of repA, encoding this protein, abolished replication. Two regions of pYVe439-80 are 76 and 70% homologous, respectively, to the copy number control antisense RNA and to the origin of replication region of R100. A mutation introduced in the pYVe439-80 DNA corresponding to the R100 sequence encoding the copy number control antisense RNA resulted in an increase in copy number, indicating a functional homology between the two replicons.
我们对来自O:9血清型小肠结肠炎耶尔森氏菌的毒力质粒pYVe439 - 80的最小复制区域进行了测序。在一段1873个核苷酸的片段上，该序列与抗性质粒R100的RepFIIA复制子序列有68%的同源性。该序列包含两个开放阅读框，repA和repB，分别编码33478道尔顿和9568道尔顿的蛋白质。这两种蛋白质的氨基酸序列分别与R100复制子的蛋白质RepA1和RepA2有77%和55%的同一性。用拷贝数突变体转化的小细胞分析表明，pYVe439 - 80的复制区域指导合成一种33千道尔顿的蛋白质。编码该蛋白质的repA的破坏消除了复制。pYVe439 - 80的两个区域分别与R100的拷贝数控制反义RNA和复制起始区域有76%和70%的同源性。在pYVe439 - 80 DNA中对应于R100编码拷贝数控制反义RNA的序列中引入的一个突变导致拷贝数增加，表明这两个复制子之间存在功能同源性。
