Fig. 5: A model for DtHtaA-mediated heme delivery by mMVs.

DQ12-45-1b secreted mMVs that loaded with DtHtaA under iron-limiting condition. After extracellular heme binding, the mMVs: (i) are recycled by DQ12-45-1b through membrane fusion, followed by transport via HmuTUV or other transporters located on the cytomembrane; (ii) fuse to phylogenetically closely related species with similar membrane thickness and constitutes, followed by heme release and transport into cytoplasm by unknown mechanisms; (iii) are less shared by other cells due to the related phylogenetically distantly homology or membrane difference. CM, cytomembrane. mM, mycomembrane, which was simplified as red bilayer here.