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The development and maturation of E. coli biofilms in flow-chambers was investigated. We found that the presence of transfer constitutive IncF plasmids induced biofilm development forming structures resembling those reported for Pseudomonas aeruginosa. The development occurred in a step-wise process: (i). attachment of cells to the substratum, (ii). clonal(More)
Bacterial conjugation is a form of type IV secretion that transports protein and DNA to recipient cells. Specific bacteriophage exploit the conjugative pili and cell envelope spanning protein machinery of these systems to invade bacterial cells. Infection by phage R17 requires F-like pili and coupling protein TraD, which gates the cytoplasmic entrance of(More)
Bacterial conjugation in Gram-negative bacteria is triggered by a signal that connects the relaxosome to the coupling protein (T4CP) and transferosome, a type IV secretion system. The relaxosome, a nucleoprotein complex formed at the origin of transfer (oriT), consists of a relaxase, directed to the nic site by auxiliary DNA-binding proteins. The nic site(More)
TraG-like proteins are potential NTP hydrolases (NTPases) that are essential for DNA transfer in bacterial conjugation. They are thought to mediate interactions between the DNA-processing (Dtr) and the mating pair formation (Mpf) systems. TraG-like proteins also function as essential components of type IV secretion systems of several bacterial pathogens(More)
Replication forks formed during rolling-circle DNA synthesis supported by a tailed form II DNA substrate in the presence of the primosome, the single-stranded DNA binding protein, and the DNA polymerase III holoenzyme (Pol III HE) that had been reconstituted from the purified subunits, beta, tau, and the gamma.delta complex, at limiting (with respect to(More)
Species-specific identification of campylobacters is problematic, primarily due to the absence of suitable biochemical assays and the existence of atypical strains. 16S rRNA gene (16S rDNA)-based identification of bacteria offers a possible alternative when phenotypic tests fail. Therefore, we evaluated the reliability of 16S rDNA sequencing for the(More)
The coordinated action of many enzymatic activities is required at the DNA replication fork to ensure the error-free, efficient, and simultaneous synthesis of the leading and lagging strands of DNA. In order to define the essential protein-protein interactions and model the regulatory pathways that control Okazaki fragment synthesis, we have reconstituted(More)
Studies with a rolling-circle DNA replication system reconstituted in vitro with a tailed form II DNA template, the DNA polymerase III holoenzyme (Pol III HE), the Escherichia coli single-stranded DNA binding protein, and the primosome, showed that within the context of a replication fork, the oligoribonucleotide primers that were formed were limited to a(More)
Bacteria commonly exchange genetic information by the horizontal transfer of conjugative plasmids. In gram-negative conjugation, a relaxase enzyme is absolutely required to prepare plasmid DNA for transit into the recipient via a type IV secretion system. Here we report a mutagenesis of the F plasmid relaxase gene traI using in-frame, 31-codon insertions.(More)
Biofilm formation on catheters is thought to contribute to persistence of catheter-associated urinary tract infections (CAUTI), which represent the most frequent nosocomial infections. Knowledge of genetic factors for catheter colonization is limited, since their role has not been assessed using physicochemical conditions prevailing in a catheterized human(More)