Deciphering the Regulatory Circuits of RA3 Replication Module - Mechanisms of the Copy Number Control.

The RA3 plasmid, the archetype of IncU incompatibility group, represents a mosaic-modular genome of 45.9 kb. The replication module encompasses and (initiator) surrounded by two long repetitive sequences DR1 and DR2 of unknown function.

Alpha-Helical Protein KfrC Acts as a Switch between the Lateral and Vertical Modes of Dissemination of Broad-Host-Range RA3 Plasmid from IncU (IncP-6) Incompatibility Group.

KfrC proteins are encoded by the conjugative broad-host-range plasmids that also encode alpha-helical filament-forming KfrA proteins as exemplified by the RA3 plasmid from the IncU incompatibility group. The RA3 variants impaired in , , or both affected the host's growth and demonstrated the altered stability in a species-specific manner. In a search for partners of the alpha-helical KfrC protein, the host's membrane proteins and four RA3-encoded proteins were found, including the filamentous KfrA protein, segrosome protein KorB, and the T4SS proteins, the coupling protein VirD4 and ATPase VirB4.

Unique Properties of the Alpha-Helical DNA-Binding Protein KfrA Encoded by the IncU Incompatibility Group Plasmid RA3 and Its Host-Dependent Role in Plasmid Maintenance.

KfrA, encoded on the broad-host-range RA3 plasmid, is an alpha-helical DNA-binding protein that acts as a transcriptional autoregulator. The KfrA operator site overlaps the promoter and is composed of five 9-bp direct repeats (DRs). Here, the biological properties of KfrA were studied using both and approaches.

Genome Structure of the Opportunistic Pathogen () and Identification of Putative Virulence Factors.

Bacteria of the genus are common components of the microbiomes of many naturally- and anthropogenically shaped environments. One species, , is unique within the genus because it is associated with opportunistic human infections. Therefore, strains of may serve as an interesting model to study the transition from a saprophytic to a pathogenic lifestyle in environmental bacteria.