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Rational engineering of Geobacter sulfurreducens electron transfer components: a foundation for building improved Geobacter-based bioelectrochemical technologies

Multiheme cytochromes have been implicated in Geobacter sulfurreducens extracellular electron transfer (EET). These proteins are potential targets to improve EET and enhance bioremediation and electrical current production by G. sulfurreducens. However, the functional characterization of multiheme c...

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Autores principales: Dantas, Joana M., Morgado, Leonor, Aklujkar, Muktak, Bruix, Marta, Londer, Yuri Y., Schiffer, Marianne, Pokkuluri, P. Raj, Salgueiro, Carlos A.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4519760/
https://www.ncbi.nlm.nih.gov/pubmed/26284042
http://dx.doi.org/10.3389/fmicb.2015.00752
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author Dantas, Joana M.
Morgado, Leonor
Aklujkar, Muktak
Bruix, Marta
Londer, Yuri Y.
Schiffer, Marianne
Pokkuluri, P. Raj
Salgueiro, Carlos A.
author_facet Dantas, Joana M.
Morgado, Leonor
Aklujkar, Muktak
Bruix, Marta
Londer, Yuri Y.
Schiffer, Marianne
Pokkuluri, P. Raj
Salgueiro, Carlos A.
author_sort Dantas, Joana M.
collection PubMed
description Multiheme cytochromes have been implicated in Geobacter sulfurreducens extracellular electron transfer (EET). These proteins are potential targets to improve EET and enhance bioremediation and electrical current production by G. sulfurreducens. However, the functional characterization of multiheme cytochromes is particularly complex due to the co-existence of several microstates in solution, connecting the fully reduced and fully oxidized states. Over the last decade, new strategies have been developed to characterize multiheme redox proteins functionally and structurally. These strategies were used to reveal the functional mechanism of G. sulfurreducens multiheme cytochromes and also to identify key residues in these proteins for EET. In previous studies, we set the foundations for enhancement of the EET abilities of G. sulfurreducens by characterizing a family of five triheme cytochromes (PpcA-E). These periplasmic cytochromes are implicated in electron transfer between the oxidative reactions of metabolism in the cytoplasm and the reduction of extracellular terminal electron acceptors at the cell's outer surface. The results obtained suggested that PpcA can couple e(−)/H(+) transfer, a property that might contribute to the proton electrochemical gradient across the cytoplasmic membrane for metabolic energy production. The structural and functional properties of PpcA were characterized in detail and used for rational design of a family of 23 single site PpcA mutants. In this review, we summarize the functional characterization of the native and mutant proteins. Mutants that retain the mechanistic features of PpcA and adopt preferential e(−)/H(+) transfer pathways at lower reduction potential values compared to the wild-type protein were selected for in vivo studies as the best candidates to increase the electron transfer rate of G. sulfurreducens. For the first time G. sulfurreducens strains have been manipulated by the introduction of mutant forms of essential proteins with the aim to develop and improve bioelectrochemical technologies.
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spelling pubmed-45197602015-08-17 Rational engineering of Geobacter sulfurreducens electron transfer components: a foundation for building improved Geobacter-based bioelectrochemical technologies Dantas, Joana M. Morgado, Leonor Aklujkar, Muktak Bruix, Marta Londer, Yuri Y. Schiffer, Marianne Pokkuluri, P. Raj Salgueiro, Carlos A. Front Microbiol Microbiology Multiheme cytochromes have been implicated in Geobacter sulfurreducens extracellular electron transfer (EET). These proteins are potential targets to improve EET and enhance bioremediation and electrical current production by G. sulfurreducens. However, the functional characterization of multiheme cytochromes is particularly complex due to the co-existence of several microstates in solution, connecting the fully reduced and fully oxidized states. Over the last decade, new strategies have been developed to characterize multiheme redox proteins functionally and structurally. These strategies were used to reveal the functional mechanism of G. sulfurreducens multiheme cytochromes and also to identify key residues in these proteins for EET. In previous studies, we set the foundations for enhancement of the EET abilities of G. sulfurreducens by characterizing a family of five triheme cytochromes (PpcA-E). These periplasmic cytochromes are implicated in electron transfer between the oxidative reactions of metabolism in the cytoplasm and the reduction of extracellular terminal electron acceptors at the cell's outer surface. The results obtained suggested that PpcA can couple e(−)/H(+) transfer, a property that might contribute to the proton electrochemical gradient across the cytoplasmic membrane for metabolic energy production. The structural and functional properties of PpcA were characterized in detail and used for rational design of a family of 23 single site PpcA mutants. In this review, we summarize the functional characterization of the native and mutant proteins. Mutants that retain the mechanistic features of PpcA and adopt preferential e(−)/H(+) transfer pathways at lower reduction potential values compared to the wild-type protein were selected for in vivo studies as the best candidates to increase the electron transfer rate of G. sulfurreducens. For the first time G. sulfurreducens strains have been manipulated by the introduction of mutant forms of essential proteins with the aim to develop and improve bioelectrochemical technologies. Frontiers Media S.A. 2015-07-30 /pmc/articles/PMC4519760/ /pubmed/26284042 http://dx.doi.org/10.3389/fmicb.2015.00752 Text en Copyright © 2015 Dantas, Morgado, Aklujkar, Bruix, Londer, Schiffer, Pokkuluri and Salgueiro. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Microbiology
Dantas, Joana M.
Morgado, Leonor
Aklujkar, Muktak
Bruix, Marta
Londer, Yuri Y.
Schiffer, Marianne
Pokkuluri, P. Raj
Salgueiro, Carlos A.
Rational engineering of Geobacter sulfurreducens electron transfer components: a foundation for building improved Geobacter-based bioelectrochemical technologies
title Rational engineering of Geobacter sulfurreducens electron transfer components: a foundation for building improved Geobacter-based bioelectrochemical technologies
title_full Rational engineering of Geobacter sulfurreducens electron transfer components: a foundation for building improved Geobacter-based bioelectrochemical technologies
title_fullStr Rational engineering of Geobacter sulfurreducens electron transfer components: a foundation for building improved Geobacter-based bioelectrochemical technologies
title_full_unstemmed Rational engineering of Geobacter sulfurreducens electron transfer components: a foundation for building improved Geobacter-based bioelectrochemical technologies
title_short Rational engineering of Geobacter sulfurreducens electron transfer components: a foundation for building improved Geobacter-based bioelectrochemical technologies
title_sort rational engineering of geobacter sulfurreducens electron transfer components: a foundation for building improved geobacter-based bioelectrochemical technologies
topic Microbiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4519760/
https://www.ncbi.nlm.nih.gov/pubmed/26284042
http://dx.doi.org/10.3389/fmicb.2015.00752
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