Bezanson G S, Iyer V N
J Bacteriol. 1975 Jul;123(1):137-46. doi: 10.1128/jb.123.1.137-146.1975.
F' Escherichia coli K-12 strains bearing the chromosomal mutation dnaB43 offer significantly less resistance to the conjugational introduction of a second F' plasmid than do nonmutant strains. Both the entry exclusion and incompatibility components of superinfection inhibition are altered. This action of dnaB43 occurs regardless of the presence of a recA-minus mutation in matings in liquid cultures and on membrane filters and is not limited to a particular set of F' plasmids. These effects are co-transducible by phage P1 with the temperature sensitivity conferred by dnaB43. The effects also occur with a strain carrying dnaB107. In the double F' strains that arise, the two plasmids exist as units autonomous of one another and the chromosome.
携带染色体突变dnaB43的F'大肠杆菌K - 12菌株，与非突变菌株相比，对第二个F'质粒的接合导入的抗性明显降低。超感染抑制的进入排斥和不相容成分均发生改变。无论在液体培养物中还是在膜滤器上进行交配时是否存在recA减号突变，dnaB43的这种作用都会发生，并且不限于特定的一组F'质粒。这些效应可通过噬菌体P1与dnaB43赋予的温度敏感性共转导。携带dnaB107的菌株也会出现这些效应。在产生的双F'菌株中，两个质粒彼此独立于染色体以单元形式存在。
