Correlation of the function of demethylmenaquinone in bacterial electron transport with its redox potential

Holländer, R

doi:10.1016/0014-5793(76)80821-6

Cited by 47 publications

(23 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The most negative E 0 = of Ϫ520 mV is of the CO 2 /CO couple (50), and the most positive E 0 = of Ϫ200 mV is of the methylene-tetrahydrofolate/methyl-tetrahydrofolate couple (51). The redox potential of menaquinone found in M. thermoacetica (14,15) is Ϫ75 mV and is thus far too positive to be involved in electron transport between CO and methylenetetrahydrofolate (52). If and how the Ech complex is involved in CO 2 reduction with H 2 to acetic acid in M. thermoacetica are important questions that need to be answered before a function of the electron-bifurcating hydrogenase HydABC in M. thermoacetica during growth on H 2 and CO 2 can definitely be assigned.…”

Section: Discussionmentioning

confidence: 99%

A Reversible Electron-Bifurcating Ferredoxin- and NAD-Dependent [FeFe]-Hydrogenase (HydABC) in Moorella thermoacetica

Wang

Huang

Kahnt

et al. 2013

Journal of Bacteriology

118

144

View full text Add to dashboard Cite

bMoorella thermoacetica was long the only model organism used to study the biochemistry of acetogenesis from CO 2 . Depending on the growth substrate, this Gram-positive bacterium can either form H 2 or consume it. Despite the importance of H 2 in its metabolism, a hydrogenase from the organism has not yet been characterized. We report here the purification and properties of an electron-bifurcating [FeFe]-hydrogenase from M. thermoacetica and show that the cytoplasmic enzyme efficiently catalyzes both H 2 formation and H 2 uptake. The purified heterotrimeric iron-sulfur flavoprotein (HydABC) catalyzed the coupled reduction of ferredoxin (Fd) and NAD ؉ with H 2 at 55°C at pH 7.5 at a specific rate of about 100 mol min ؊1 mg protein ؊1 and the reverse reaction, the coupled reduction of protons to H 2 with reduced ferredoxin and NADH, at a specific rate of about 10 mol min ؊1 mg protein ؊1 in the stoichiometry Fd ox ؉ NAD ؉ ؉ 2H 2 ª Fd red 2؊ ؉ NADH ؉ 3H ؉ . When ferredoxin from Clostridium pasteurianum, NAD ؉ , and the enzyme were incubated at pH 7.0 under 100% H 2 in the gas phase (E 0 = ‫؍‬ ؊414 mV), more than 95% of the ferredoxin (E 0 = ‫؍‬ ؊400 mV) was reduced, which indicated that ferredoxin reduction with H 2 is driven by the exergonic reduction of NAD ؉ (E 0 = ‫؍‬ ؊320 mV) with H 2 . In the absence of NAD ؉ , ferredoxin was not reduced. We identified the genes encoding HydABC within the transcriptional unit hydCBAX and mapped the transcription start site.

show abstract

Section: Discussionmentioning

confidence: 99%

A Reversible Electron-Bifurcating Ferredoxin- and NAD-Dependent [FeFe]-Hydrogenase (HydABC) in Moorella thermoacetica

Wang

Huang

Kahnt

et al. 2013

Journal of Bacteriology

118

144

View full text Add to dashboard Cite

show abstract

“…In contrast, organisms such as M . luteus, Bacillus alcalophilus and Chorobium species, which display 'Rieske' signals of low redox potential [19], all possess menaquinones [28] whose E"' values (-74 mV, [30]) are considerably lower than corresponding values for ubiquinones (+ 112 mV) or plastoquinones (+ 113 mV; [29,301). Thus it appears that E"' values of 'Rieske' iron-sulphur centres and of quinone species acting as electron donors have adapted in such a way as to maintain efficient electron transfer.…”

Section: Discussionmentioning

confidence: 99%

Study of the respiratory chain in Micrococcus luteus (lysodeikticus) by electron‐spin‐resonance spectroscopy

Crowe

Owen

Cammack

1983

European Journal of Biochemistry

View full text Add to dashboard Cite

Low-temperature electron spin resonance spectroscopy was used to investigate the redox centres of Micrococcus luteus membranes, Three different types of iron-sulphur centres were distinguished. Two of these, a [4Fe-4SI3 +-type cluster giving rise to a signal at g = 2.01 in the oxidized state and a [2Fe-2S] cluster with a spectrum at g = 2.03 and 1.93 in the reduced state, were attributable to succinate dehydrogenase. Another, generating signals in the reduced state at g = 2.027, 1.90 and 1.78 was identified as a 'Rieske' iron-sulphur centre. This latter cluster had a mid-point potential (pH 7.0) of + 130 mV. In addition, signals characteristic of high-spin ferric haem (g = 6.20), low-spin ferric haem (g = 3.67,3.36 and 3.01) and Cu2+ (g == 2.18 and 2.02) were also detected. The ferric-haem features, together with the Cu2 + and 'Rieske' centres, were enriched in membrane residues insoluble in Triton X-100, which are known from difference spectroscopy to contain cytochromes b-560, c-550 and a-60 1 (aa3 oxidase). The signals demonstrated by electron spin resonance for M . luteus membranes showed marked similarities to those documented for the complexes 11,111, and IV of mitochondria. However, signals analogous to complex I (NADH-ubiquinone reductase) could not be demonstrated for M . luteus membranes.Low-temperature electron spin resonance (ESR) spectroscopy has been extremely useful in the analysis of the redox centres in the respiratory and photosynthetic electron transport chains of eukaryotic cells [ I -41. In recent years, the technique has also been applied to the study of membrane-bound redox systems in several gram-negative bacteria [4 -81. However, the membranes of gram-positive microorganisms have not been subjected to detailed examination by this method -a situation which is somewhat surprising, in view of the relative simplicity of this membrane system and the ease with which the structure can be isolated [9].We have chosen to study the respiratory chain of the model gram-positive bacterium Micrococcus luteus (formerly lysodeikticus). Previous studies of a biochemical and immunochemical nature have indicated that this aerobic heterotroph has an electron transport chain which contains a number of substrate dehydrogenases (NADH dehydrogenase, succinate dehydrogenase and malate dehydrogenase) together with two b-type cytochromes (cytochrome b-556 and cytochrome b-560), cytochrome c-550 and cytochrome aa3 oxidase [lo-121. There is also some evidence for the presence of a 'Rieske'-type ironsulphur protein and a cytochrome o-type alternate oxidase [13, 141. In the present investigation we extend the preliminary biophysical analysis by Burbaev et al. [14] MATERIALS AND METHODS Growth of cells and preparation of membranesCells of Micrococcus luteus (NCTC 2665) were grown aerobically in peptone/water/yeast extract medium [9] at 30 "C with shaking (200rev/min). Cells were harvested in late exponential phase (approximately 14 h) and were washed twice in 50 mM Tris/HCl buffer (pH 7.5). Cells were lysed osmotica...

show abstract

“…3B), while no obvious color change was observed in the rGO culture. A candidate electron mediator that has a similar redox potential is a dimethyl menaquinone in gammaproteobacteria (+36 mV) (Holländer, 1976). These results indicated that different carbon materials generate differing levels of electricity and can alter the electron-transfer pathways.…”

Section: Electricity Production From Adww Using the Rgo/gf Complexmentioning

confidence: 99%

Microbially reduced graphene oxide shows efficient electricity ecovery from artificial dialysis wastewater

Goto

Yoshida

2017

J. Gen. Appl. Microbiol.

View full text Add to dashboard Cite

Correlation of the function of demethylmenaquinone in bacterial electron transport with its redox potential

Cited by 47 publications

References 13 publications

A Reversible Electron-Bifurcating Ferredoxin- and NAD-Dependent [FeFe]-Hydrogenase (HydABC) in Moorella thermoacetica

A Reversible Electron-Bifurcating Ferredoxin- and NAD-Dependent [FeFe]-Hydrogenase (HydABC) in Moorella thermoacetica

Study of the respiratory chain in Micrococcus luteus (lysodeikticus) by electron‐spin‐resonance spectroscopy

Microbially reduced graphene oxide shows efficient electricity ecovery from artificial dialysis wastewater

Contact Info

Product

Resources

About