Pseudomonas aeruginosa T6SS secretes an oxygen-binding hemerythrin to facilitate competitive growth under microaerobic conditions.

Pseudomonas aeruginosa is a prominent respiratory pathogen in cystic fibrosis (CF) patients, thriving in the hypoxic airway mucus. Previous studies have established the role of the oxygen-binding hemerythrin, Mhr, in enhancing P. aeruginosa's fitness under microaerobic conditions.

H3-T6SS of Pseudomonas aeruginosa PA14 contributes to environmental adaptation via secretion of a biofilm-promoting effector.

Microbial species often occur in complex communities and exhibit intricate synergistic and antagonistic interactions. To avoid predation and compete for favorable niches, bacteria have evolved specialized protein secretion systems. The type VI secretion system (T6SS) is a versatile secretion system widely distributed among Gram-negative bacteria that translocates effectors into target cells or the extracellular milieu via various physiological processes.

T6SS translocates a micropeptide to suppress STING-mediated innate immunity by sequestering manganese.

Cellular ionic concentrations are a central factor orchestrating host innate immunity, but no pathogenic mechanism that perturbs host innate immunity by directly targeting metal ions has yet been described. Here, we report a unique virulence strategy of () involving modulation of the availability of Mn, an immunostimulatory metal ion in host cells. We showed that the type VI secretion system (T6SS) delivered a micropeptide, TssS, into host cells to enhance its virulence.

Aerobactin-Mediated Iron Acquisition Enhances Biofilm Formation, Oxidative Stress Resistance, and Virulence of .

Aerobactin is a citrate-hydroxamate siderophore that is critical for the virulence of pathogenic enteric bacteria. However, although the aerobactin-producing - operon is distributed widely in the genomes of species, none of the pathogenic spp. was found to produce aerobactin.

Siderophore-Mediated Iron Acquisition Enhances Resistance to Oxidative and Aromatic Compound Stress in JMP134.

Many bacteria secrete siderophores to enhance iron uptake under iron-restricted conditions. In this study, we found that JMP134, a well-known aromatic pollutant-degrading bacterium, produces an unknown carboxylate-type siderophore named cupriabactin to overcome iron limitation. Using genome mining, targeted mutagenesis, and biochemical analysis, we discovered an operon containing six open reading frames () in the JMP134 genome that encodes proteins required for the biosynthesis and uptake of cupriabactin.