Fig. 1

Expression of soluble OmcA and MtrF. a Concentrated supernatants of S. oneidensis expressing soluble versions of MtrF or OmcA in comparison with the wild type. Equivalent volumes were concentrated equally. The different filling levels in the tubes result from the removal of different sample volumes. The supernatant of the mtrF_sol expressing strain shows a more prominent red color. b Heme stain of an SDS gel with concentrated supernatant of S. oneidensis cells expressing soluble versions of MtrF or OmcA in comparison to the wild type. The supernatant of the mtrF_sol and omcA_sol expressing strains yields a strong heme signal that can be correlated to the molecular weight of the proteins