Grant A J, Bird P I, Pittard J
J Bacteriol. 1980 Nov;144(2):758-65. doi: 10.1128/jb.144.2.758-765.1980.
From a group of naturally occurring antibiotic resistance plasmids, a number of plasmids were identified which were incompatible with members of incompatibility group P and also incompatibility group I alpha or I gamma. These plasmids also exhibited strong entry exclusion with members of group P only and showed a host range which resembled that of plasmids of group I rather than those of group P. Segregants of a number of these plasmids appeared to have lost some of the incompatability and/or surface exclusion functions. Studies of nucleic acid homology indicated that these plasmids were very similar to one another. They exhibited 15 to 20% nucleic acid homology with representatives of the I alpha and I gamma groups, yet showed less than 2% homology with the group P plasmid RP4.
从一组天然存在的抗生素抗性质粒中，鉴定出了一些质粒，这些质粒与不相容群P的成员不相容，也与不相容群Iα或Iγ不相容。这些质粒还仅对群P的成员表现出强烈的进入排斥，并且显示出的宿主范围类似于群I的质粒而非群P的质粒。其中一些质粒的分离子似乎失去了一些不相容性和/或表面排斥功能。核酸同源性研究表明，这些质粒彼此非常相似。它们与Iα和Iγ群的代表表现出15%至20%的核酸同源性，但与群P质粒RP4的同源性不到2%。
