DsbC

DsbC is a bacterial outer membrane protein that plays a crucial role in the transport of siderophores, which are iron-chelating molecules. Siderophores are essential for the acquisition of iron, a vital nutrient for bacterial growth and survival. DsbC is a member of the Dsb family of proteins, which are involved in the biogenesis of disulfide bonds in proteins. However, DsbC's primary function is not related to disulfide bond formation, but rather to the transport of siderophores across the outer membrane.

DsbC is a homotetramer, with each subunit consisting of a single transmembrane domain and a periplasmic domain. The transmembrane domain spans the outer membrane, while the periplasmic domain faces the periplasm, the space between the inner and outer membranes. The periplasmic domain of DsbC contains a binding site for siderophores, which allows the protein to capture and transport these molecules across the outer membrane.

The transport of siderophores by DsbC is an active process, requiring energy in the form of ATP. The energy is provided by the proton motive force, which drives the transport of siderophores against their concentration gradient. Once the siderophores are transported across the outer membrane, they can be taken up by the bacterium through specific receptors.

DsbC is not only important for bacterial iron acquisition but also for the host-pathogen interactions. Many bacterial pathogens, such as Pseudomonas aeruginosa and Burkholderia cepacia, produce siderophores and use DsbC for their transport. The inhibition of DsbC activity can be a potential therapeutic strategy for treating infections caused by these pathogens.