Streptococcus plasmid pAM alpha 1 is a composite of two separable replicons, one of which is closely related to Bacillus plasmid pBC16-猫眼课题宝

链球菌质粒 pAM α 1 是两个可分离复制子的复合体，其中一个与芽孢杆菌质粒 pBC16 密切相关

DOI：

10.1128/jb.155.2.607-615.1983

发表时间：

1983

期刊：

Journal of Bacteriology

影响因子：

3.2

通讯作者：

中科院分区：

生物学3区

文献类型：

作者：

J. Perkins;P. Youngman

A tetracycline resistance plasmid of Streptococcus faecalis, pAM alpha 1, is shown to contain two independent sets of replication functions, separated from each other on either side by short (300- to 400-base-pair) sequences of homology. The homologous sequences are oriented as direct repeats and therefore permit the dissociation of pAM alpha 1 into its component replicons, referred to here as pAM alpha 1 delta 1 and pAM alpha 1 delta 2, as the reciprocal products of a simple intramolecular recombination. pAM alpha 1 delta 1 is a 4.6-kilobase plasmid which carries the tet gene, and pAM alpha 1 delta 2 is a 5.1-kilobase plasmid which carries no known selectable marker. pAM alpha 1 delta 1 is shown to replicate efficiently in Bacillus subtilis and to confer tetracycline resistance on Bacillus hosts. We demonstrate by restriction mapping analysis that pAM alpha 1 delta 1 is virtually identical to a 4.6-kilobase tetracycline resistance plasmid of Bacillus cereus, pBC16, which is known to show extensive homology to plasmid isolates from Staphylococcus species (such as pUB110), as well as from other Bacillus species. The pAM alpha 1 delta 1-pBC16-pUB110 replicon thus exists naturally in at least three different gram-positive genera, indicating that these plasmids have a high degree of interspecific functional adaptability and supporting the view that plasmid DNA is commonly exchanged among many species of gram-positive bacteria in their natural environments.