5.B.15.  The Bacterial Cable Electron Conduction (BCEC) Family 

'Electric cables' are involved in bioenergetic processes of living cells (Ptushenko 2020). Microbial electric currents can occur over centimeter distances, and these electric currents couple spatially separated biogeochemical processes in marine sediment (Nielsen et al. 2010). This new group of bacteria, allowing electric currents to flow over macroscopic distances has been called cable bacteria. Nanowires and conductive structures of cable bacteria serve to solve a special problem of membrane bioenergetics: they connect two redox half-reactions. Unlike membrane 'cables', their function is electron transfer in the course of oxidative phosphorylation for the generation of membrane energy. The protein nature of these cables (at least of some of them) has been suggested as has the involvement of PilA. No protein wires for long-distance electron transport had been previously known in living systems (Ptushenko 2020).