To engineer novel proteins and polypeptide based assemblies that can be used in molecular electronic devices and nanotechnology in general. This involves understanding, at a fundamental level, how metal cofactors, particularly heme, is delivered to proteins in vivo and, in the case of c-type cytochromes, how heme is covalently attached to protein. It also involves understanding how functional protein units can be assembled into larger nanoscale assemblies that gain function through the proximity of the constituent monomers.