Mickel S, Ohtsubo E, Bauer W
Gene. 1977;2(3-4):193-210. doi: 10.1016/0378-1119(77)90017-8.
Small, autonomously replicating plasmids derived by in vivo recombination from R-factor R12 (= R100) have been structurally mapped by heteroduplex formation between the plasmids and an R-factor which is structurally closely related to R6-5. Recombination resulting in generation of the small resistance-free plasmids occurs between the (IS1)b insertion sequence and various other sites on the opposite side of an origin of replication. A larger R12-derived plasmid pSM17, carrying streptomycin (Sm), sulfadiazole (Sa), and chloramphenicol (Cm) resistances, has recombined in a similar manner but at the (IS1)a sequence. A new structural coordinate origin for R100 and for partially homologous R-factors is proposed based upon the location of the (IS1)b sequence.
通过体内重组从R因子R12（=R100）衍生而来的小型自主复制质粒，已通过质粒与结构上与R6 - 5密切相关的R因子之间形成异源双链体进行了结构图谱绘制。导致产生小型无抗性质粒的重组发生在（IS1）b插入序列与复制起点另一侧的各种其他位点之间。一个更大的源自R12的质粒pSM17，携带链霉素（Sm）、磺胺嘧啶（Sa）和氯霉素（Cm）抗性，以类似方式但在（IS1）a序列处发生了重组。基于（IS1）b序列的位置，提出了R100和部分同源R因子的新结构坐标原点。
