Hinchliffe E, Nugent M E, Vivian A
J Gen Microbiol. 1980 Dec;121(2):411-8. doi: 10.1099/00221287-121-2-411.
Acinetobacter calcoaceticus strain EBF65/65 harbours a cryptic plasmid, pAV2, which has been shown by electrophoretic separation on agarose gels to have a molecular mass of approximately 13.5 megadaltons (Md). Transfer of the previously described sex factor pAV1 (Hinchliffe & Vivian, 1980 a,b) from the hospital strainJC17 into strains possessing pAV2 occurs only at a low frequency, whereas transfer to similar strains lacking pAV2 occurs at a much higher frequency. In EBF65/65, pAV1 may be present in strains possessing or lacking pAV2; pAV1 strains lacking pAV2 correspond to strains previously described as pAV1a (Hinchliffe & Vivian, 1980b) whereas pAV1 strains which also possess pAV2 correspond to pAB1b strains. The genetic evidence presented here is consistent with the hypothesis that pAV2 specifies a host restriction and modification system that is active against pAV1. Physical evidence from agarose gel electrophoresis indicates that pAV1 corresponds to a band of approximately 85 Md in strain JC17. The corresponding band in strains of EBF65/65 is difficult to distinguish because of the presence of a further cryptic plasmid band of approximately 88 Md, designated pAV3. A small cryptic plasmid of approximately 6 Md, designated pAV4, is reported for EBF65/65.
醋酸钙不动杆菌菌株EBF65/65含有一个隐蔽质粒pAV2，经琼脂糖凝胶电泳分离显示其分子量约为13.5兆道尔顿（Md）。先前描述的性因子pAV1（Hinchliffe和Vivian，1980年a，b）从医院菌株JC17转移到含有pAV2的菌株中仅以低频率发生，而转移到缺乏pAV2的类似菌株中则以高得多的频率发生。在EBF65/65中，pAV1可能存在于含有或缺乏pAV2的菌株中；缺乏pAV2的pAV1菌株对应于先前描述为pAV1a的菌株（Hinchliffe和Vivian，1980b），而同时也含有pAV2的pAV1菌株对应于pAB1b菌株。这里提供的遗传学证据与pAV2指定了一个对pAV1有活性的宿主限制和修饰系统这一假设一致。琼脂糖凝胶电泳的物理证据表明，pAV1在菌株JC17中对应于一条约85 Md的条带。由于存在另一条约88 Md的隐蔽质粒条带（命名为pAV3），EBF65/65菌株中的相应条带难以区分。报道了EBF65/65含有一个约6 Md的小隐蔽质粒，命名为pAV4。
