Gennaro M L
Public Health Research Institute, New York, NY 10016.
Proc Natl Acad Sci U S A. 1993 Jun 15;90(12):5529-33. doi: 10.1073/pnas.90.12.5529.
Rolling circle replication of the Staphylococcus aureus plasmid pT181 requires interaction of the RepC initiator protein with the origin of replication (the ori site). A second site named cmp, which is distant from ori, is thought to stimulate replication, since a mutant pT181 plasmid lacking cmp cannot coexist with a cmp+ wild-type plasmid. Second-site mutations compensating for the loss of cmp were shown to map in repC. The compensatory mutations produced RepC proteins that, unlike the wild-type, either failed to discriminate between cmp+ and cmp- plasmids or preferred cmp- to cmp+ plasmids. These studies demonstrate that cmp stimulates the interaction of the replication initiator protein with the origin and therefore enhances DNA replication from a distance.
金黄色葡萄球菌质粒pT181的滚环复制需要复制起始蛋白RepC与复制起点（ori位点）相互作用。一个名为cmp的第二位点，它距离ori较远，被认为可刺激复制，因为缺少cmp的突变型pT181质粒不能与cmp +野生型质粒共存。已证明补偿cmp缺失的第二位点突变定位于repC中。补偿性突变产生的RepC蛋白，与野生型不同，要么无法区分cmp +和cmp -质粒，要么更喜欢cmp -质粒而非cmp +质粒。这些研究表明，cmp刺激复制起始蛋白与起点的相互作用，因此从远处增强DNA复制。
