Figure 2.

The model of T6SS-mediated stress response to environmental pressure. (A) B. thailandensis T6SS effector TseZ as a proteinaceous zincophore interacts with heme transporter HmuR to acquire zinc, which facilitates Zn²⁺ transportation to resist oxidative stress. HmuR forms intramolecular disulfide bond to transport zinc instead of heme under oxidative stress. (B) B. thailandensis T6SS effector TseM transports Mn²⁺ to resist oxidative stress with the help of outer membrane transporter MnoT. TseM is secreted into the extracellular milieu to scavenging Mn²⁺ and deliver it to MnoT when bacteria encounter oxidative stress.