The goal of this project is to identify and characterize the functions present in the PColV.K30 REPI region that are associated with control of its replication. This replicon is part of a replication.aerobactin iron.transport unit that we found to be conserved in plasmid carrying the aerobactin iron-transport system genes. The REPI replication region endows the cells with incompatibility properties corresponding to the IncFI group and must have been instrumental in the preservation and epidemiological spread of the aerobactin iron-transport system. Although it is a replicon frequently found in bacterial plasmid, little is known on the mechanisms controlling its replication and the mechanisms that result in the expression of the IncFI incompatibility phenotype. The following experiments are being performed: 1. Analysis of the product(s) involved in the control of replication of REPI containing plasmid. 2. Characterization of a trans.acting protein RepI which is necessary for REPI replication, and its mechanism of action. 3. Elucidation of the role of the novel incompatibility region incF and the already known incE in the mechanisms of REPI incompatibility that result in the IncFI phenotype. Dr. Crosa's work on this bacterial plasmid to date hasestablished the overall framework of the elements replication, and the proposed future work deals with further elaboration of the features he has found. Understanding of how this replicon functions will certainly advance our understanding of plasmid replication and compatibility between different plasmid. In addition this study may improve our understanding of how these plasmid spread and are maintained in bacterial populations.
