Stirling C J, Stewart G, Sherratt D J
Institute of Genetics, University of Glasgow, UK.
Mol Gen Genet. 1988 Sep;214(1):80-4. doi: 10.1007/BF00340183.
The heritable stability of the multicopy plasmid ColE1 and its natural relatives, requires the presence in the plasmid of a site (cer in ColE1) that acts as a substrate for site-specific recombination, thereby maintaining plasmids in the monomeric state. Multimerization, promoted by homologous recombination, leads to plasmid loss. Here we show that the Escherichia coli chromosome encodes at least two unlinked functions that act on cer and its analogous sites, to promote stabilizing site-specific recombination. One of these functions is encoded by a gene residing on a cosmid that also contains the argI and pyrB genes, mapping it to the 96-97 min region of the E. coli map.
多拷贝质粒ColE1及其天然亲缘质粒的遗传稳定性，要求质粒中存在一个位点（ColE1中的cer），该位点作为位点特异性重组的底物，从而使质粒维持在单体状态。由同源重组促进的多聚化会导致质粒丢失。在这里，我们表明大肠杆菌染色体编码至少两种不连锁的功能，这些功能作用于cer及其类似位点，以促进稳定的位点特异性重组。其中一种功能由位于黏粒上的一个基因编码，该黏粒还包含argI和pyrB基因，将其定位到大肠杆菌图谱的96 - 97分钟区域。
