Annotation inferences using phylogenetic trees
Electronic Gene Ontology annotations created by ARBA machine learning models
Combined Automated Annotation using Multiple IEA Methods
Type VI secretion system in Pseudomonas aeruginosa: secretion and multimerization of VgrG proteins.
-
VgrG1b release does not require clpV1, clpV2 or clpV3, and the vgrG1b mutant secretes Hcp1, VgrG1a and VgrG1c normally; the authors conclude VgrG1b neither needs nor supports the H1-T6SS for secretion.
"Overall, these results indicate that although vgrG1b is co-expressed with H1-T6SS genes, VgrG1b neither impacts secretion of components of the H1-T6SS nor requires H1-T6SS components for its own secretion."
The VgrG proteins are "à la carte" delivery systems for bacterial type VI effectors.
-
VgrG1b contributes independently to interbacterial competition, and reintroducing vgrG1b alone into a triple vgrG1abc mutant restores that activity, together with the PA0099 protein encoded in its cluster.
"Finally, VgrG1b-dependent killing is detectable upon complementation of a triple vgrG1abc mutant."
The Pseudomonas aeruginosa T6SS-VgrG1b spike is topped by a PAAR protein eliciting DNA damage to bacterial competitors.
-
The PAAR-domain protein Tse7 caps the VgrG1b spike, residues at the PAAR-VgrG1b interface are required for VgrG1b-dependent delivery, and that delivery depends on the H1-T6SS cluster.
"Tse7 sits on the tip of the VgrG1b spike"