Cryo-EM reveals the structural basis of long-range electron transport in a cytochrome-based bacterial nanowire

Commun Biol. 2019 Jun 19:2:219. doi: 10.1038/s42003-019-0448-9. eCollection 2019.

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. Using cryo-electron microscopy, we have characterized nanowires from conductive G. sulfurreducens pili preparations that are composed solely of head-to-tail stacked monomers of the six-heme C-type cytochrome OmcS. The unique fold of OmcS - closely wrapped around a continuous stack of hemes that can serve as an uninterrupted path for electron transport - generates a scaffold that supports the unbranched chain of hemes along the central axis of the filament. We present here, at 3.4 Å resolution, the structure of this cytochrome-based filament and discuss its possible role in long-range biological electron transport.

Keywords: Bioenergetics; Cellular microbiology; Soil microbiology.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Cryoelectron Microscopy / methods*
  • Cytochromes c / physiology*
  • Electron Transport*
  • Fimbriae, Bacterial / metabolism
  • Fimbriae, Bacterial / ultrastructure*
  • Geobacter / metabolism*
  • Nanowires

Substances

  • Cytochromes c