Exploring the biochemistry at the extracellular redox frontier of bacterial mineral Fe(III) respiration

Authors

David J. Richardson, University of East AngliaFollow
Marcus J. Edwards, University of East Anglia
Gaye F. White, University of East Anglia
Nanakow Baiden, University of East Anglia
Robert S. Hartshorne, University of East Anglia
James K. Fredrickson, Pacific Northwest National LaboratoryFollow
Liang Shi, Pacific Northwest National LaboratoryFollow
John M. Zachara, Pacific Northwest National LaboratoryFollow
Andrew J. Gates
University of East Anglia, University of East Anglia
Thomas Clarke, University of East AngliaFollow

Date of this Version

2012

Citation

Biochem. Soc. Trans. (2012) 40, 493–500; doi:10.1042/BST20120018

Abstract

Many species of the bacterial Shewanella genus are notable for their ability to respire in anoxic environments utilizing insoluble minerals of Fe(III) and Mn(IV) as extracellular electron acceptors. In Shewanella oneidensis, the process is dependent on the decahaem electron-transport proteins that lie at the extracellular face of the outer membrane where they can contact the insoluble mineral substrates. These extracellular proteins are charged with electrons provided by an inter-membrane electron-transfer pathway that links the extracellular face of the outer membrane with the inner cytoplasmic membrane and thereby intracellular electron sources. In the present paper, we consider the common structural features of two of these outer-membrane decahaem cytochromes, MtrC and MtrF, and bring this together with biochemical, spectroscopic and voltammetric data to identify common and distinct properties of these prototypical members of different clades of the outer-membrane decahaem cytochrome superfamily.