Gryczan T J, Hahn J, Contente S, Dubnau D
J Bacteriol. 1982 Nov;152(2):722-35. doi: 10.1128/jb.152.2.722-735.1982.
pE194, a 3.5-kilobase multicopy plasmid, confers resistance to the macrolide-lincosamide-streptogramin B antibiotics in Bacillus subtilis. By molecular cloning and deletion analysis we have identified a replication segment on the physical map of this plasmid, which consists of about 900 to 1,000 base pairs. This segment contains the replication origin. It also specifies a trans-acting function (rep) required for the stable replication of pE194 and a negatively acting copy control function which is the product of the cop gene. The target sites for the rep and cop gene products are also within this region. Two incompatibility determinants have been mapped on the pE194 genome and their properties are described. One (incA) resides within the replication region and may be identical to cop. incB, not located in the replication region, expresses incompatibility toward a copy control mutant (cop-6) but not toward the wild-type replicon.
pE194是一种3.5千碱基的多拷贝质粒，可赋予枯草芽孢杆菌对大环内酯 - 林可酰胺 - 链阳菌素B类抗生素的抗性。通过分子克隆和缺失分析，我们在该质粒的物理图谱上鉴定出一个复制区段，其由约900至1000个碱基对组成。该区段包含复制起点。它还指定了pE194稳定复制所需的反式作用功能（rep）和作为cop基因产物的负性作用的拷贝控制功能。rep和cop基因产物的靶位点也在该区域内。已在pE194基因组上绘制了两个不相容性决定簇，并描述了它们的特性。一个（incA）位于复制区域内，可能与cop相同。incB不位于复制区域，对拷贝控制突变体（cop - 6）表现出不相容性，但对野生型复制子则不然。
