Trojan horselike T6SS effector TepC mediates both interference competition and exploitative competition

Area of Science:

• Microbiology
• Bacterial Genetics
• Ecology

Background:

• The type VI secretion system (T6SS) is a key bacterial virulence factor.
• T6SS effectors mediate interference and exploitation competition.
• No single T6SS effector has been known to mediate both competition types.

Purpose of the Study:

• To identify and characterize novel T6SS effectors with dual functions.
• To investigate the roles of TepC in microbial community dynamics.
• To elucidate the molecular mechanisms of TepC-mediated competition.

Main Methods:

• Genetic analysis of Yersinia pseudotuberculosis.
• Biochemical assays for DNase and siderophore activity.
• Competition assays in controlled microbial environments.

Main Results:

• Identified TepC, a unique T6SS-1 effector in Yersinia pseudotuberculosis.
• TepC functions as a siderophore, binding iron for exploitative competition.
• TepC possesses DNase activity, enabling interference competition.
• TepC exhibits a "lure-to-kill" mechanism, benefiting kin cells and harming non-kin.

Conclusions:

• TepC is a bifunctional T6SS effector mediating both interference and exploitation competition.
• TepC's dual activity contributes to the stability of microbial communities.
• This study reveals a novel mechanism for resource acquisition and competitor control in bacteria.