Measuring heme-hopping electron transfer through a biological nanowire

Over the past few decades, filamentous structures have been identified in bacteria associated with long-range electron transport. The electrically conductive pili (e-pili) or outer membrane extensions have been observed to allow electron transport to occur over many micrometers, potentially allowing for novel biological electrical applications. Diverse research groups have been working to understand the structural basis for long range electron transfer in these systems. In the nanowire under study here, electron transfer is mediated by nanoscale cytochrome assemblies, where multiple heme-bearing proteins come into close contact.