Part:BBa_K4849016

MtrA - periplasmic decaheme cytochrome protein

A periplasmic decaheme cytochrome protein facilitating transport of electrons from the periplasm to outside of the cell. MtrA protein sits on the inside of the outer membrane of the cell. (as seen in the illustration)

Metal-reducing microorganisms such as Shewanella oneidensis MR-1 and Geobacter metallireducens have evolved an innate EET pathway that makes them ideal for bioelectricity applications. The most characterised EET pathway in S. oneidensis MR-1 includes MtrCAB complex. Based on the current understanding, the electrons extracted from the oxidation of a substrate are ultimately transferred to the periplasmic decaheme cytochrome MtrA during anaerobic respiration. Subsequent electron transfer to the outer membrane β-barrel protein MtrB places MtrA in direct contact with MtrC. MtrC is re-oxidised by reducing terminal electron acceptors, such as electrodes, via direct or mediated electron transfer.

Image made in Biorender.com

 

 

Image by: White, Gaye, et al. "Rapid Electron Exchange between Surface-Exposed Bacterial Cytochromes and Fe(III) Minerals." Proceedings of the National Academy of Sciences, vol. 110, no. 16, 2013, pp. 6346-6351

 

References:

1. Ross, Daniel E., et al. "Characterization of protein-protein interactions involved in iron reduction by Shewanella oneidensis MR-1." Applied and environmental microbiology 73.18 (2007): 5797-5808.

2. Breuer, Marian, et al. "Multi-haem cytochromes in Shewanella oneidensis MR-1: structures, functions and opportunities." Journal of The Royal Society Interface 12.102 (2015): 20141117.