Agrobacterium tumefaciens transfers DNA and proteins to a plant cell through a type IV secretion apparatus assembled by the VirB proteins. All VirB proteins localized to a cell pole, although these conclusions are in dispute. To study subcellular location of the VirB proteins and to identify determinants of their subcellular location, we tagged two proteins, VirB4 and VirB11, with the visual ma...

Physiological adaptation of intracellular bacteria is critical for timely interaction with eukaryotic host cells. One mechanism of adaptation, the stringent response, is induced by nutrient stress via its effector molecule (p)ppGpp, synthesized by the action of RelA/SpoT homologues. The intracellular pathogen Brucella spp., causative agent of brucellosis, possesses a gene homologous to relA/spo...

The products of the Brucella abortus virB gene locus, which are highly similar to conjugative DNA transfer system, enable the bacterium to replicate within macrophage vacuoles. The replicative phagosome is thought to be established by the interaction of a substrate of the VirB complex with macrophages, although the substrate and its host cellular target have not yet been identified. We report h...

Agrobacterium tumefaciens translocates T-DNA through a polar VirB/D4 type IV secretion (T4S) system. VirC1, a factor required for efficient T-DNA transfer, bears a deviant Walker A and other sequence motifs characteristic of ParA and MinD ATPases. Here, we show that VirC1 promotes conjugative T-DNA transfer by stimulating generation of multiple copies per cell of the T-DNA substrate (T-complex)...

Type IV secretion systems (T4SSs) are transporters of Gram-negative bacteria that mediate interbacterial DNA transfer, and translocation of virulence factors into eukaryotic host cells. The alpha-proteobacterial genus Bartonella comprises arthropod-borne pathogens that colonize endothelial cells and erythrocytes of their mammalian reservoir hosts, thereby causing long-lasting intraerythrocytic ...

Agrobacterium tumefaciens A281 induces large, rapidly appearing tumors on a variety of plants and has a wider host range than other strains of A. tumefaciens. By using Tn3HoHo1 transposon mutagenesis and complementation analysis, a 2.5-kilobase DNA fragment which is responsible for the supervirulence phenotype was identified in the virulence (vir) region of the Ti plasmid. This fragment contain...

Introduction: In addition to Helicobacter pylori, non-Helicobacter pylori helicobacters (NHPHs) have been diagnosed in the humans stomach that caused gastrointestinal diseases. This study aimed to evaluate the coinfection of H. pylori with NHPHs species in patients with gastric disorders in Iran.   Materials & Methods: This cross-sectional study was performed on 421 gastric biopsies form dysp...

Jenny Ure University of Edinburgh