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Title: Mtr Extracellular Electron Transfer Pathways in Fe(III)-reducing or Fe(II)-oxidizing Bacteria: A Genomic Perspective

Abstract

Originally discovered in the dissimilatory metal-reducing bacterium Shewanella oneidensis MR-1 (MR-1), the Mtr (i.e., metal-reducing) pathway exists in all characterized strains of metal-reducing Shewanella. The protein components identified to date for the Mtr pathway of MR-1 include four multi-heme c-type cytochromes (c-Cyts), CymA, MtrA, MtrC and OmcA, and a porin-like, outer membrane protein MtrB. They are strategically positioned along the width of the MR-1 cell envelope to mediate electron transfer from the quinone/quinol pool in the inner-membrane to the Fe(III)-containing minerals external to the bacterial cells. A survey of microbial genomes revealed homologues of the Mtr pathway in other dissimilatory Fe(III)-reducing bacteria, including Aeromonas hydrophila, Ferrimonas balearica and Rhodoferax ferrireducens, and in the Fe(II)-oxidizing bacteria Dechloromonas aromatica RCB, Gallionella capsiferriformans ES-2 and Sideroxydans lithotrophicus ES-1. The widespread distribution of Mtr pathways in Fe(III)-reducing or Fe(II)-oxidizing bacteria emphasizes the importance of this type of extracellular electron transfer pathway in microbial redox transformation of Fe. Their distribution in these two different functional groups of bacteria also emphasizes the bi-directional nature of electron transfer reactions carried out by the Mtr pathways. The characteristics of the Mtr pathways may be shared by other pathways used by microorganisms for exchanging electrons with their extracellular environments.

Authors:
; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1057828
Report Number(s):
PNNL-SA-86720
KP1702030
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Journal Name:
Biochemical Society: Transactions, 40(6):1261-1267
Additional Journal Information:
Journal Name: Biochemical Society: Transactions, 40(6):1261-1267
Country of Publication:
United States
Language:
English
Subject:
Dissimilatory Fe(III) reduction; Shewanella oneidensis MR-1; Fe(II) oxidation; Mtr extracellular electron transfer pathway; c-type cytochromes; genomics

Citation Formats

Shi, Liang, Rosso, Kevin M, Zachara, John M, and Fredrickson, Jim K. Mtr Extracellular Electron Transfer Pathways in Fe(III)-reducing or Fe(II)-oxidizing Bacteria: A Genomic Perspective. United States: N. p., 2012. Web. doi:10.1042/BST20120098.
Shi, Liang, Rosso, Kevin M, Zachara, John M, & Fredrickson, Jim K. Mtr Extracellular Electron Transfer Pathways in Fe(III)-reducing or Fe(II)-oxidizing Bacteria: A Genomic Perspective. United States. doi:10.1042/BST20120098.
Shi, Liang, Rosso, Kevin M, Zachara, John M, and Fredrickson, Jim K. Sat . "Mtr Extracellular Electron Transfer Pathways in Fe(III)-reducing or Fe(II)-oxidizing Bacteria: A Genomic Perspective". United States. doi:10.1042/BST20120098.
@article{osti_1057828,
title = {Mtr Extracellular Electron Transfer Pathways in Fe(III)-reducing or Fe(II)-oxidizing Bacteria: A Genomic Perspective},
author = {Shi, Liang and Rosso, Kevin M and Zachara, John M and Fredrickson, Jim K},
abstractNote = {Originally discovered in the dissimilatory metal-reducing bacterium Shewanella oneidensis MR-1 (MR-1), the Mtr (i.e., metal-reducing) pathway exists in all characterized strains of metal-reducing Shewanella. The protein components identified to date for the Mtr pathway of MR-1 include four multi-heme c-type cytochromes (c-Cyts), CymA, MtrA, MtrC and OmcA, and a porin-like, outer membrane protein MtrB. They are strategically positioned along the width of the MR-1 cell envelope to mediate electron transfer from the quinone/quinol pool in the inner-membrane to the Fe(III)-containing minerals external to the bacterial cells. A survey of microbial genomes revealed homologues of the Mtr pathway in other dissimilatory Fe(III)-reducing bacteria, including Aeromonas hydrophila, Ferrimonas balearica and Rhodoferax ferrireducens, and in the Fe(II)-oxidizing bacteria Dechloromonas aromatica RCB, Gallionella capsiferriformans ES-2 and Sideroxydans lithotrophicus ES-1. The widespread distribution of Mtr pathways in Fe(III)-reducing or Fe(II)-oxidizing bacteria emphasizes the importance of this type of extracellular electron transfer pathway in microbial redox transformation of Fe. Their distribution in these two different functional groups of bacteria also emphasizes the bi-directional nature of electron transfer reactions carried out by the Mtr pathways. The characteristics of the Mtr pathways may be shared by other pathways used by microorganisms for exchanging electrons with their extracellular environments.},
doi = {10.1042/BST20120098},
journal = {Biochemical Society: Transactions, 40(6):1261-1267},
number = ,
volume = ,
place = {United States},
year = {2012},
month = {12}
}