Functions of the REPI Region of Plasmid Co1V-K30 in Escherichia coli K12

REPI区域是铁运输系统的一部分-复制 我们发现在细菌质粒中是保守的， 需氧肌动蛋白铁转运基因。 REPI复制区域 赋予细胞不相容性， IncFI集团，并必须在维护 和流行病的传播。 这个复制子 经常在细菌质粒中发现，但知之甚少 控制其复制和维护的机制， 以及导致表达的机制， IncFI表型。 我们成功地分析和表征了 参与复制控制的DNA序列和产物 含REPI的质粒;纯化并表征了反式- 作用蛋白RepI，REPI复制所必需的，并解剖 REPI不相容性决定因素。 此外，我们有 最近发现，细胞的铁浓度和 Fur（铁吸收调节）基因的表达是 一种新的调节电路， 的REPI。 我们现在正在进行结构-功能研究， RepI蛋白，并分析其复制调控机制 通过Fur和细胞的铁状态确定REPI复制子的数量。 %%% 这一制度是研究 复制起始及其与环境的关系 因素

The REPI region is part of an iron transport system-replication unit that we found to be conserved in bacterial plasmids carrying the aerobactin iron transport genes. The REPI replication region endows the cell with incompatibility properties corresponding to the IncFI group and must have been instrumental in the preservation and epidemiological spread of the aerobactin system. This replicon is frequently found in bacterial plasmids, however little is known on the mechanism controlling its replication and maintenance, as well as on the mechanisms that result in the expression of the IncFI phenotype. We successfully analyzed and characterized the DNA sequences and product(s) involved in the control of replication of REPI-containing plasmids; purified and characterized the trans- acting protein RepI, essential for REPI replication, and dissected the REPI incompatibility determinants. Furthermore, we have recently found that the iron concentration of the cell and expression of the fur (ferric uptake regulation) gene are part of a novel regulatory circuit that acts in the control of copy number of REPI. We are now performing structure-function studies on the RepI protein, and analyzing the mechanism of regulation of the copy number REPI replicons by Fur and the iron status of the cell. %%% This system stands out as a model to study the regulation of initiation of replication and its relationship to environmental factors.