Proton Transport in the Outer‐Membrane Flavocytochrome Complex Limits the Rate of Extracellular Electron Transport
Abstract
The microbial transfer of electrons to extracellularly located solid compounds, termed extracellular electron transport (EET), is critical for microbial electrode catalysis. Although the components of the EET pathway in the outer membrane (OM) have been identified, the role of electron/cation coupling in EET kinetics is poorly understood. We studied the dynamics of proton transport associated with EET in an OM flavocytochrome complex in Shewanella oneidensis MR‐1. Using a whole‐cell electrochemical assay, a significant kinetic isotope effect (KIE) was observed following the addition of deuterated water (D2O). The removal of a flavin cofactor or key components of the OM flavocytochrome complex significantly increased the KIE in the presence of D2O to values that were significantly larger than those reported for proton channels and ATP synthase, thus indicating that proton transport by OM flavocytochrome complexes limits the rate of EET.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 29, 2017
- Source ID
- 10.1002/anie.201704241
Entities
People
- Akihiro Okamoto
- Kazuhito Hashimoto
- Shafeer Kalathil
- Yoshihide Tokunou
Organizations
- Japan Society for the Promotion of Science
- Office of Naval Research Global
- University of Tokyo