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Title: The oxygen reduction reaction catalyzed by Synechocystis sp. PCC 6803 flavodiiron proteins

Abstract

Photosynthetic flavodiiron (Flv) proteins bind flavin and non-heme Fe cofactors and catalyze the oxygen reduction reaction (ORR) coupled to oxidation of reduced pyridine nucleotides during photosynthetic growth. The activity of Flvs have also been observed to form an important catalytic redox loop with water oxidation necessary for preserving photosynthetic electron transport function in cyanobacteria. To determine how these functions may be related, we investigated the kinetic properties of Flv1 and Flv3 from Synechocystis sp. PCC 6803. Under an oxygen atmosphere, Flv1 and Flv3 were found to catalyze ORR with either NADH or NADPH as the electron donor. Reaction velocity curves were sigmoidal and Flv binding of NAD(P)H was cooperative. Based on mass spectrometry generated structural models, each Flv assembles as a homodimer with two oxidoreductase domains capable of binding two molecules of NAD(P)H per subunit, and the flavins are arranged to support electron transfer to the diiron sites for oxygen reduction. Titrations with NAD(P)H resulted in reduction of the diiron site without the accumulation of stable, reduced flavin intermediates. Altogether, the results provide new insights on the properties of Flv1 and Flv3 that enable tight control of reactivity for the complete reduction of oxygen to water, and in this capacitymore » help preserve photosynthetic electron transport function.« less

Authors:
ORCiD logo [1]; ORCiD logo [1];  [2];  [2]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [2]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  2. Montana State Univ., Bozeman, MT (United States)
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1569446
Alternate Identifier(s):
OSTI ID: 1562731
Report Number(s):
NREL/JA-2700-74436
Journal ID: ISSN 2398-4902; SEFUA7
Grant/Contract Number:  
AC36-08GO28308
Resource Type:
Accepted Manuscript
Journal Name:
Sustainable Energy & Fuels
Additional Journal Information:
Journal Name: Sustainable Energy & Fuels; Journal ID: ISSN 2398-4902
Publisher:
Royal Society of Chemistry
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; kinetic properties; catalysis; photosynthetic flavodiron; oxygen reduction reaction

Citation Formats

Brown, Katherine A., Guo, Zhanjun, Tokmina-Lukaszewska, Monika, Scott, Liam W., Lubner, Carolyn E., Smolinski, Sharon, Mulder, David W., Bothner, Brian, and King, Paul W. The oxygen reduction reaction catalyzed by Synechocystis sp. PCC 6803 flavodiiron proteins. United States: N. p., 2019. Web. doi:10.1039/C9SE00523D.
Brown, Katherine A., Guo, Zhanjun, Tokmina-Lukaszewska, Monika, Scott, Liam W., Lubner, Carolyn E., Smolinski, Sharon, Mulder, David W., Bothner, Brian, & King, Paul W. The oxygen reduction reaction catalyzed by Synechocystis sp. PCC 6803 flavodiiron proteins. United States. doi:10.1039/C9SE00523D.
Brown, Katherine A., Guo, Zhanjun, Tokmina-Lukaszewska, Monika, Scott, Liam W., Lubner, Carolyn E., Smolinski, Sharon, Mulder, David W., Bothner, Brian, and King, Paul W. Thu . "The oxygen reduction reaction catalyzed by Synechocystis sp. PCC 6803 flavodiiron proteins". United States. doi:10.1039/C9SE00523D.
@article{osti_1569446,
title = {The oxygen reduction reaction catalyzed by Synechocystis sp. PCC 6803 flavodiiron proteins},
author = {Brown, Katherine A. and Guo, Zhanjun and Tokmina-Lukaszewska, Monika and Scott, Liam W. and Lubner, Carolyn E. and Smolinski, Sharon and Mulder, David W. and Bothner, Brian and King, Paul W.},
abstractNote = {Photosynthetic flavodiiron (Flv) proteins bind flavin and non-heme Fe cofactors and catalyze the oxygen reduction reaction (ORR) coupled to oxidation of reduced pyridine nucleotides during photosynthetic growth. The activity of Flvs have also been observed to form an important catalytic redox loop with water oxidation necessary for preserving photosynthetic electron transport function in cyanobacteria. To determine how these functions may be related, we investigated the kinetic properties of Flv1 and Flv3 from Synechocystis sp. PCC 6803. Under an oxygen atmosphere, Flv1 and Flv3 were found to catalyze ORR with either NADH or NADPH as the electron donor. Reaction velocity curves were sigmoidal and Flv binding of NAD(P)H was cooperative. Based on mass spectrometry generated structural models, each Flv assembles as a homodimer with two oxidoreductase domains capable of binding two molecules of NAD(P)H per subunit, and the flavins are arranged to support electron transfer to the diiron sites for oxygen reduction. Titrations with NAD(P)H resulted in reduction of the diiron site without the accumulation of stable, reduced flavin intermediates. Altogether, the results provide new insights on the properties of Flv1 and Flv3 that enable tight control of reactivity for the complete reduction of oxygen to water, and in this capacity help preserve photosynthetic electron transport function.},
doi = {10.1039/C9SE00523D},
journal = {Sustainable Energy & Fuels},
number = ,
volume = ,
place = {United States},
year = {2019},
month = {9}
}

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Works referenced in this record:

Genes Encoding A-Type Flavoproteins Are Essential for Photoreduction of O2 in Cyanobacteria
journal, February 2003


EasySpin, a comprehensive software package for spectral simulation and analysis in EPR
journal, January 2006