The plant pathogenPectobacterium atrosepticumcontains a functional formate hydrogenlyase-2 complex

SummaryPectobacterium atrosepticumSCRI1043 is a phytopathogenic gram-negative enterobacterium. Genomic analysis has identified that genes required for both respiration and fermentation are expressed under anaerobic conditions. One set of anaerobically expressed genes is predicted to encode an important but poorly-understood membrane-bound enzyme termed formate hydrogenlyase-2 (FHL-2), which has fascinating evolutionary links to the mitochondrial NADH dehydrogenase (Complex I). In this work, molecular genetic and biochemical approaches were taken to establish that FHL-2 is fully functional inP. atrosepticumand is the major source of molecular hydrogen gas generated by this bacterium. The FHL-2 complex was shown to comprise a rare example of an active [NiFe]-hydrogenase-4 (Hyd-4) isoenzyme, itself linked to an unusual selenium-free formate dehydrogenase in the final complex. In addition, further genetic dissection of the genes encoding the predicted membrane domain of FHL-2 established surprisingly that the majority of genes encoding this domain are not required for physiological hydrogen production activity. Overall, this study presentsP. atrosepticumas a new model bacterial system for understanding anaerobic formate and hydrogen metabolism in general, and FHL-2 function and structure in particular.Significance StatementPectobacterium atrospecticumcontains the genes for the formate hydrogenlyase-2 enzyme, considered the ancient progenitor of mitochondrial respiratory Complex I. In this study, the harnessing ofP. atrosepticumas a new model system for understanding bacterial hydrogen metabolism has accelerated new knowledge in FHL-2 and its component parts. Importantly, those component parts include an unusual selenium-free formate dehydrogenase and a complicated [NiFe]-hydrogenase-4 with a large membrane domain. FHL-2 is established as the major source of molecular hydrogen produced under anaerobic conditions byP. atrospectium, however surprisingly some components of the membrane domain were not essential for this activity.

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Reshaping of bacterial molecular hydrogen metabolism contributes to the outgrowth of commensal E. coli during gut inflammation

eLife ◽

10.7554/elife.58609 ◽

2021 ◽

Vol 10 ◽

Author(s):

Elizabeth R Hughes ◽

Maria G Winter ◽

Laice Alves da Silva ◽

Matthew K Muramatsu ◽

Angel G Jimenez ◽

...

Keyword(s):

Molecular Hydrogen ◽

Intestinal Inflammation ◽

Electron Acceptors ◽

Hydrogen Metabolism ◽

Bacterial Genomes ◽

Infectious Colitis ◽

E Coli ◽

Genes Encoding ◽

Inflammatory Bowel ◽

Hydrogenase 2

The composition of gut-associated microbial communities changes during intestinal inflammation, including an expansion of Enterobacteriaceae populations. The mechanisms underlying microbiota changes during inflammation are incompletely understood. Here, we analyzed previously published metagenomic datasets with a focus on microbial hydrogen metabolism. The bacterial genomes in the inflamed murine gut and in patients with inflammatory bowel disease contained more genes encoding predicted hydrogen-utilizing hydrogenases compared to communities found under non-inflamed conditions. To validate these findings, we investigated hydrogen metabolism of Escherichia coli, a representative Enterobacteriaceae, in mouse models of colitis. E. coli mutants lacking hydrogenase-1 and hydrogenase-2 displayed decreased fitness during colonization of the inflamed cecum and colon. Utilization of molecular hydrogen was in part dependent on respiration of inflammation-derived electron acceptors. This work highlights the contribution of hydrogenases to alterations of the gut microbiota in the context of non-infectious colitis.

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Kinetics for formate dehydrogenase of Escherichia coli formate-hydrogenlyase

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)92760-2 ◽

1991 ◽

Vol 266 (21) ◽

pp. 13731-13736

Author(s):

M.J. Axley ◽

D.A. Grahame

Keyword(s):

Escherichia Coli ◽

Formate Dehydrogenase ◽

Formate Hydrogenlyase

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Mutations in human nuclear genes encoding for subunits of mitochondrial respiratory complex I: the NDUFS4 gene

Gene ◽

10.1016/s0378-1119(01)00810-1 ◽

2002 ◽

Vol 286 (1) ◽

pp. 149-154 ◽

Cited By ~ 40

Author(s):

Vittoria Petruzzella ◽

Sergio Papa

Keyword(s):

Complex I ◽

Nuclear Genes ◽

Respiratory Complex ◽

Mitochondrial Respiratory Complex ◽

Genes Encoding ◽

Respiratory Complex I ◽

Mitochondrial Respiratory

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Proton translocation pathways and inter-subunit coupling in the membrane domain of respiratory complex I

Biochimica et Biophysica Acta (BBA) - Bioenergetics ◽

10.1016/j.bbabio.2018.09.125 ◽

2018 ◽

Vol 1859 ◽

pp. e41

Author(s):

Max E. Mühlbauer ◽

Andrea Di Luca ◽

Patricia Saura ◽

Ville R.I. Kaila

Keyword(s):

Complex I ◽

Proton Translocation ◽

Membrane Domain ◽

Respiratory Complex ◽

Respiratory Complex I

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Susceptibility of the Formate Hydrogenlyase Reaction to the Protonophore CCCP Depends on the Total Hydrogenase Composition

Inorganics ◽

10.3390/inorganics8060038 ◽

2020 ◽

Vol 8 (6) ◽

pp. 38

Author(s):

Janik Telleria Marloth ◽

Constanze Pinske

Keyword(s):

Complex I ◽

H2 Production ◽

Proton Pumping ◽

Fermentative Hydrogen Production ◽

Iron Sulfur ◽

Formate Hydrogenlyase ◽

Respiratory Complex I ◽

Fermentative Hydrogen ◽

Pumping Activity ◽

Higher Sensitivity

Fermentative hydrogen production by enterobacteria derives from the activity of the formate hydrogenlyase (FHL) complex, which couples formate oxidation to H2 production. The molybdenum-containing formate dehydrogenase and type-4 [NiFe]-hydrogenase together with three iron-sulfur proteins form the soluble domain, which is attached to the membrane by two integral membrane subunits. The FHL complex is phylogenetically related to respiratory complex I, and it is suspected that it has a role in energy conservation similar to the proton-pumping activity of complex I. We monitored the H2-producing activity of FHL in the presence of different concentrations of the protonophore CCCP. We found an inhibition with an apparent EC50 of 31 µM CCCP in the presence of glucose, a higher tolerance towards CCCP when only the oxidizing hydrogenase Hyd-1 was present, but a higher sensitivity when only Hyd-2 was present. The presence of 200 mM monovalent cations reduced the FHL activity by more than 20%. The Na+/H+ antiporter inhibitor 5-(N-ethyl-N-isopropyl)-amiloride (EIPA) combined with CCCP completely inhibited H2 production. These results indicate a coupling not only between Na+ transport activity and H2 production activity, but also between the FHL reaction, proton import and cation export.

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The infrared response of molecular hydrogen gas to ultraviolet radiation - High-density regions

The Astrophysical Journal ◽

10.1086/167193 ◽

1989 ◽

Vol 338 ◽

pp. 197 ◽

Cited By ~ 308

Author(s):

A. Sternberg ◽

A. Dalgarno

Keyword(s):

Ultraviolet Radiation ◽

Molecular Hydrogen ◽

Hydrogen Gas ◽

High Density

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Dissection of the Hydrogen Metabolism of the EnterobacteriumTrabulsiella guamensis: Identification of a Formate-Dependent and Essential Formate Hydrogenlyase Complex Exhibiting Phylogenetic Similarity to Complex I

Journal of Bacteriology ◽

10.1128/jb.00160-19 ◽

2019 ◽

Vol 201 (12) ◽

Cited By ~ 3

Author(s):

Ute Lindenstrauß ◽

Constanze Pinske

Keyword(s):

Fossil Fuels ◽

Biochemical Characterization ◽

Model Organism ◽

Attractive Alternative ◽

Hydrogen Metabolism ◽

Content Type ◽

E Coli ◽

Formate Hydrogenlyase ◽

Alternative Carbon Source

ABSTRACTTrabulsiella guamensisis a nonpathogenic enterobacterium that was isolated from a vacuum cleaner on the island of Guam. It has one H2-oxidizing Hyd-2-type hydrogenase (Hyd) and encodes an H2-evolving Hyd that is most similar to the uncharacterizedEscherichia coliformate hydrogenlyase (FHL-2Ec) complex. TheT. guamensisFHL-2 (FHL-2Tg) complex is predicted to have 5 membrane-integral and between 4 and 5 cytoplasmic subunits. We showed that the FHL-2Tgcomplex catalyzes the disproportionation of formate to CO2and H2. FHL-2Tghas activity similar to that of theE. coliFHL-1Eccomplex in H2evolution from formate, but the complex appears to be more labile upon cell lysis. Cloning of the entire 13-kbp FHL-2Tgoperon in the heterologousE. colihost has now enabled us to unambiguously prove FHL-2Tgactivity, and it allowed us to characterize the FHL-2Tgcomplex biochemically. Although the formate dehydrogenase (FdhH) genefdhFis not contained in the operon, the FdhH is part of the complex, and FHL-2Tgactivity was dependent on the presence ofE. coliFdhH. Also, in contrast toE. coli,T. guamensiscan ferment the alternative carbon source cellobiose, and we further investigated the participation of both the H2-oxidizing Hyd-2Tgand the H2-forming FHL-2Tgunder these conditions.IMPORTANCEBiological H2production presents an attractive alternative for fossil fuels. However, in order to compete with conventional H2production methods, the process requires our understanding on a molecular level. FHL complexes are efficient H2producers, and the prototype FHL-1Eccomplex inE. coliis well studied. This paper presents the first biochemical characterization of an FHL-2-type complex. The data presented here will enable us to solve the long-standing mystery of the FHL-2Eccomplex, allow a first biochemical characterization ofT. guamensis’s fermentative metabolism, and establish this enterobacterium as a model organism for FHL-dependent energy conservation.

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Regulation of tartrate metabolism by TtdR and relation to the DcuS–DcuR-regulated C4-dicarboxylate metabolism of Escherichia coli

Microbiology ◽

10.1099/mic.0.031401-0 ◽

2009 ◽

Vol 155 (11) ◽

pp. 3632-3640 ◽

Cited By ~ 12

Author(s):

Ok Bin Kim ◽

Julia Reimann ◽

Hanna Lukas ◽

Uwe Schumacher ◽

Jan Grimpo ◽

...

Keyword(s):

Escherichia Coli ◽

Promoter Region ◽

Anaerobic Conditions ◽

Two Component System ◽

Two Component ◽

Fumarate Respiration ◽

Mutual Regulation ◽

Genes Encoding ◽

Type Gene ◽

Tartrate Dehydratase

Escherichia coli catabolizes l-tartrate under anaerobic conditions to oxaloacetate by the use of l-tartrate/succinate antiporter TtdT and l-tartrate dehydratase TtdAB. Subsequently, l-malate is channelled into fumarate respiration and degraded to succinate by the use of fumarase FumB and fumarate reductase FrdABCD. The genes encoding the latter pathway (dcuB, fumB and frdABCD) are transcriptionally activated by the DcuS–DcuR two-component system. Expression of the l-tartrate-specific ttdABT operon encoding TtdAB and TtdT was stimulated by the LysR-type gene regulator TtdR in the presence of l- and meso-tartrate, and repressed by O2 and nitrate. Anaerobic expression required a functional fnr gene, and nitrate repression depended on NarL and NarP. Expression of ttdR, encoding TtdR, was repressed by O2, nitrate and glucose, and positively regulated by TtdR and DcuS. Purified TtdR specifically bound to the ttdR–ttdA promoter region. TtdR was also required for full expression of the DcuS–DcuR-dependent dcuB gene in the presence of tartrate. Overall, expression of the ttdABT genes is subject to l-/meso-tartrate-dependent induction, and to aerobic and nitrate repression. The control is exerted directly at ttdA and in addition indirectly by regulating TtdR levels. TtdR recognizes a subgroup (l- and meso-tartrate) of the stimuli perceived by the sensor DcuS, which responds to all C4-dicarboxylates; both systems apparently communicate by mutual regulation of the regulatory genes.

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Estimation of the hydrogen concentration in rat tissue using an airtight tube following the administration of hydrogen via various routes

Scientific Reports ◽

10.1038/srep05485 ◽

2014 ◽

Vol 4 (1) ◽

Cited By ~ 38

Author(s):

Chi Liu ◽

Ryosuke Kurokawa ◽

Masayuki Fujino ◽

Shinichi Hirano ◽

Bunpei Sato ◽

...

Keyword(s):

Hydrogen Concentration ◽

Intravenous Administration ◽

Molecular Hydrogen ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Intraperitoneal Administration ◽

Hydrogen Gas ◽

Rat Blood ◽

Beneficial Effects ◽

Rat Tissue

Abstract Hydrogen exerts beneficial effects in disease animal models of ischemia-reperfusion injury as well as inflammatory and neurological disease. Additionally, molecular hydrogen is useful for various novel medical and therapeutic applications in the clinical setting. In the present study, the hydrogen concentration in rat blood and tissue was estimated. Wistar rats were orally administered hydrogen super-rich water (HSRW), intraperitoneal and intravenous administration of hydrogen super-rich saline (HSRS) and inhalation of hydrogen gas. A new method for determining the hydrogen concentration was then applied using high-quality sensor gas chromatography, after which the specimen was prepared via tissue homogenization in airtight tubes. This method allowed for the sensitive and stable determination of the hydrogen concentration. The hydrogen concentration reached a peak at 5 minutes after oral and intraperitoneal administration, compared to 1 minute after intravenous administration. Following inhalation of hydrogen gas, the hydrogen concentration was found to be significantly increased at 30 minutes and maintained the same level thereafter. These results demonstrate that accurately determining the hydrogen concentration in rat blood and organ tissue is very useful and important for the application of various novel medical and therapeutic therapies using molecular hydrogen.

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