Functional characterization of VirB/VirD4 and Icm/Dot type IV secretion systems from the plant-pathogenic bacterium .

Introduction: Many Gram-negative plant- and animal-pathogenic bacteria employ type IV secretion (T4S) systems to transport proteins or DNA/protein complexes into eukaryotic or bacterial target cells. T4S systems have been divided into minimized and expanded T4S systems and resemble the VirB/VirD4 T4S system from the plant pathogen and the Icm/Dot T4S system from the human pathogen , respectively. The only known plant pathogen with both types of T4S systems is which is the causal agent of bacterial spot disease on pepper and tomato plants.

Recognition of a translocation motif in the regulator HpaA from is controlled by the type III secretion chaperone HpaB.

The Gram-negative plant-pathogenic bacterium is the causal agent of bacterial spot disease in pepper and tomato plants. Pathogenicity of depends on a type III secretion () system which translocates effector proteins into plant cells and is associated with an extracellular pilus and a translocon in the plant plasma membrane. Effector protein translocation is activated by the cytoplasmic chaperone HpaB which presumably targets effectors to the system.

HrpB7 from Xanthomonas campestris pv. vesicatoria is an essential component of the type III secretion system and shares features of HrpO/FliJ/YscO family members.

The Gram-negative bacterium Xanthomonas campestris pv. vesicatoria translocates effector proteins via a type III secretion system (T3SS) into eukaryotic cells. The T3SS spans both bacterial membranes and consists of more than 20 proteins, 9 of which are conserved in plant and animal pathogens and constitute the core subunits of the secretion apparatus.

A TAL-Based Reporter Assay for Monitoring Type III-Dependent Protein Translocation in Xanthomonas.

Gram-negative plant- and animal-pathogenic bacteria use type III secretion (T3S) systems to translocate effector proteins into eukaryotic host cells. Type III-dependent delivery of effector proteins depends on a secretion and translocation signal, which is often located in the N-terminal protein region and is not conserved on the amino acid level. Translocation signals in effector proteins have been experimentally confirmed by employing reporter proteins, which are specifically activated inside eukaryotic cells.