Structural insights into the disulfide isomerase and chaperone activity of TrbB of the F plasmid type IV secretion system.

Bacteria have evolved elaborate mechanisms to thrive in stressful environments. F-like plasmids in gram-negative bacteria encode for a multi-protein Type IV Secretion System (T4SS) that is functional for bacterial proliferation and adaptation through the process of conjugation. The periplasmic protein TrbB is believed to have a stabilizing chaperone role in the T4SS assembly, with TrbB exhibiting disulfide isomerase (DI) activity.