Structure of a cytochrome-based bacterial nanowire

Abstract Electrically conductive pili from Geobacter species, termed bacterial “nanowires”, are intensely studied for their biological significance and potential in the development of new materials. We have characterized a unique nanowire from conductive G. sulfurreducens pili preparations by cryo-electron microscopy composed solely of the c-type cytochrome OmcS. We present here, at 3.4 Å resolution, a novel structure of a cytochrome-based filament and discuss its possible role in long-range biological electron transport. Summary sentence Cryo-electron microscopy reveals the remarkable assembly of a c-type cytochrome into filaments comprising a heme-based bacterial nanowire.