FIG. 2.

Schematic describing the experimental setup used to examine the interactions between hematite (Fe₂O₃) and purified S. oneidensis MR-1 outer membrane cytochromes MtrC (A) and OmcA (B). MtrC and OmcA are drawn arbitrarily here since their three-dimensional structures are not known. Purified recombinant proteins were covalently attached to a gold substrate via terminal Cys residues and were probed with a hematite-functionalized AFM tip in PBS buffer at pH 7.4.