Danilevich V N, Kostiuchenko D A, Negriĭ N V, Shtannikov A V
Mol Biol (Mosk). 1984 Jul-Aug;18(4):1111-20.
When analysing the antibiotic resistant, temperature-independent derivatives of Proteus mirabilis cells, carrying the plasmid RP1ts12, a derivative of the latter (pRP19.6) with an elevated frequency of integration into E. coli K12 chromosome, has been isolated. The structure and properties of pRP19.6 was studied. As revealed from the data of structural and genetic analyses pRP19.6 is identical to the factor R68.45 described earlier by Haas and Holloway. Similarly to R68.45, the plasmid under study contains two copies of IS21 sequence and mobilises nonconjugative plasmid pBR325 with high efficiency. Using the temperature sensitive replication of pRP19.6, frequency of it's integration into the chromosomes of E. coli rec+ and recA- stains is determined. It is demonstrated that the clones carrying the plasmid in integrated state are Hfr-strains. The possibilities to use the temperature sensitive R68.45 like plasmid for isolation of Hfr-strains in the broad range of gram-negative bacteria and for insertional inactivation of chromosomal genes are discussed.
在分析携带质粒RP1ts12的奇异变形杆菌细胞的抗生素抗性、温度不依赖衍生物时，分离出了后者的一种衍生物（pRP19.6），它整合到大肠杆菌K12染色体中的频率有所提高。对pRP19.6的结构和特性进行了研究。从结构和遗传分析数据可知，pRP19.6与Haas和Holloway之前描述的因子R68.45相同。与R68.45类似，所研究的质粒包含两个IS21序列拷贝，并能高效动员非接合性质粒pBR325。利用pRP19.6的温度敏感复制，确定了它整合到大肠杆菌rec+和recA-菌株染色体中的频率。结果表明，携带整合状态质粒的克隆是高频重组（Hfr）菌株。讨论了使用温度敏感的类似R68.45的质粒在广泛的革兰氏阴性细菌中分离Hfr菌株以及对染色体基因进行插入失活的可能性。
