Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.6.99.5 (NADH dehydrogenase)
2,135 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Electron paramagnetic resonance spectra at 8-60 K of NADH-reduced membrane particles prepared from Paracoccus denitrificans grown anaerobically with nitrate as terminal electron acceptor show the presence of iron-sulfur centers 1-4 in the NADH-ubiquinone segment of the respiratory chain. In addition resonance lines at g = 2.058, g = 1.953 and g = 1.88 are detectable in the spectra of succinate-reduced membranes at 15 K, which are attributed to the iron-sulfur-containing nitrate reductase. 2. Sulphate-limited growth under anaerobic conditions does not affect the iron-sulfur pattern of NADH dehydrogenase or nitrate reductase. Furthermore respiratory chain-linked electron transport and its inhibition by rotenone are not influenced. These results contrast those observed for sulphate-limited growth of P. denitrificans under aerobic conditions [Eur. J. Biochem. (1977) 81, 267-275]. 3. Proton translocation studies of whole cells indicate that nitrite increases the proton conductance of the cytoplasmic membrane, resulting in a collapse of the proton gradient across the membrane. Nitrite accumulates under anaerobic growth conditions with nitrate as terminal electron acceptor; the extent of accumulation depends on the specific growth conditions. Thus the low efficiencies of respiratory chain-linked energy conservation observed during nitrate respiration [Arch. Microbiol. (1977) 112, 17-23] can be explained by the uncoupling action of nitrite.
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PMID:Anaerobic respiration and energy conservation in Paracoccus denitrificans. Functioning of iron-sulfur centers and the uncoupling effect of nitrite. 3 82

A membrane-bound NADH dehydrogenase, solubilized and partially purified from a marine bacterium Photobacterium phosphoreum, contains FAD as the prosthetic group, and is specific for NADH. Ferricyanide, various other redox dyes and cytochrome c can act as electron acceptors. The enzymatic activity when assayed with electron acceptors other than cytochrome c, is activated by monovalent cations (Na+ and K+) and deactivated by high concentrations of monovalent anions (SCN-, NO3-, and Cl-) but not by phosphate ions. The enzymatic reaction follows a ping-pong mechanism and kinetic analysis of the enzyme showed that the activation by monovalent cations is due to increase of affinity of the enzyme for substrates; Vm was not affected. The increase of affinity was 62- and 46-fold for NADH and 57- and 31-fold for 2,6-dichlorophenol indophenol in the presence of Na+ and K+, respectively. On the other hand, NADH-cytochrome c reductase activity of the enzyme was strongly inhibited by these cations.
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PMID:Properties and kinetics of salt activation of a membrane-bound NADH dehydrogenase from a marine bacterium Photobacterium phosphoreum. 72 93

Assimilatory nitrate reductase from Chlorella is a homotetramer which contains one of each of the prosthetic groups FAD, heme, and molybdenum per subunit. Besides the reduction of nitrate by NADH, nitrate reductase also catalyzes the partial activities NADH:cytochrome c reductase, NADH:ferricyanide reductase, and reduced methyl viologen:nitrate reductase. Incubation of native nitrate reductase with either trypsin, Staphylococcus aureus V8 protease, or a natural inactivator protease from corn results in a loss of NADH:nitrate reductase and NADH:cytochrome c reductase activities but no loss of reduced methyl viologen:nitrate reductase activity. Incubation of nitrate reductase with V8 protease or corn inactivator protease resulted in two different products, each of which retained a different partial activity. Reduced methyl viologen:nitrate reductase activity was associated with a homotetrameric fragment of about 260 kDa which contained heme and molybdenum but no FAD. The molecular mass of native nitrate reductase determined under the same conditions was 375 kDa. NADH:ferricyanide reductase activity was associated with a monomeric species of approximately 30 kDa which contained FAD and the NADH-binding site. These results are consistent with a structure-function model of nitrate reductase which has the following features: FAD/NADH-binding domains exposed on the surface of the molecule, a protease-sensitive hinge region which connects the nitrate-reducing and NADH dehydrogenase moieties, and the quaternary structure maintained via association sites on the heme/molybdenum domain.
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PMID:Functional domains of assimilatory NADH:nitrate reductase from Chlorella. 301 63

In Escherichia coli the expression of the nuo genes encoding the proton pumping NADH dehydrogenase I is stimulated by the presence of fumarate during anaerobic respiration. The regulatory sites required for the induction by fumarate, nitrate and O2 are located at positions around -309, -277, and downstream of -231 bp, respectively, relative to the transcriptional-start site. The fumarate regulator has to be different from the O2 and nitrate regulators ArcA and NarL. For growth by fumarate respiration, the presence of NADH dehydrogenase I was essential, in contrast to aerobic or nitrate respiration which used preferentially NADH dehydrogenase II. The electron transport from NADH to fumarate strongly decreased in a mutant lacking NADH dehydrogenase I. The mutant used acetyl-CoA instead of fumarate to an increased extent as an electron acceptor for NADH, and excreted ethanol. Therefore, NADH dehydrogenase I is essential for NADH-->fumarate respiration, and is able to use menaquinone as an electron acceptor. NADH-->dimethylsulfoxide respiration is also dependent on NADH dehydrogenase I. The consequences for energy conservation by anaerobic respiration with NADH as a donor are discussed.
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PMID:Requirement for the proton-pumping NADH dehydrogenase I of Escherichia coli in respiration of NADH to fumarate and its bioenergetic implications. 906 59

The ndh gene of Escherichia coli encodes the non-proton-translocating NADH dehydrogenase II. Expression of the ndh gene is subject to a complex network of regulatory controls at the transcriptional level. Under anaerobic conditions ndh is repressed by the regulator of fumarate and nitrate reduction (FNR). However, in the absence of FNR, ndh expression is activated by the amino acid response regulator (Arr) during anaerobic growth in rich medium. Expression of the ndh gene varies during the growth cycle in response to the intracellular concentration of the heat-stable DNA-binding protein, Fis. In this work two additional heat-stable proteins, integration host factor (IHF) and the histone-like protein HU were found to interact with the ndh promoter. IHF was shown to bind at three sites centred at +26, -17 and -58 in the ndh promoter (Kd = 10(-8) M), to prevent open-complex formation and to repress ndh transcription in vitro. Studies with an ndh-lacZ fusion confirmed that IHF represses ndh expression in vivo. Two putative binding sites for Arr, which overlap the two FNR boxes in the ndh promoter, were identified. Studies with the FNR-activated and amino-acid-inducible asparaginase II gene (ansB) showed that IHF and a component of the Arr-containing fraction (but not HU) interact with the corresponding ansB promoter.
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PMID:Regulation of the ndh gene of Escherichia coli by integration host factor and a novel regulator, Arr. 930 70

Nitric oxide interactions with iron are the most important biological reactions in which NO participates. Reversible binding to ferrous haem iron is responsible for the observed activation of guanylate cyclase and inhibition of cytochrome oxidase. Unlike carbon monoxide or oxygen, NO can also bind reversibly to ferric iron. The latter reaction is responsible for the inhibition of catalase by NO. NO reacts with the oxygen adduct of ferrous haem proteins (e.g. oxyhaemoglobin) to generate nitrate and ferric haem; this reaction is responsible for the majority of NO metabolism in the vasculature. NO can also interact with iron-sulphur enzymes (e.g. aconitase, NADH dehydrogenase). This review describes the underlying kinetics, thermodynamics, mechanisms and biological role of the interactions of NO with iron species (protein and non-protein bound). The possible significance of iron reactions with reactive NO metabolites, in particular peroxynitrite and nitroxyl anion, is also discussed.
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PMID:Nitric oxide and iron proteins. 1032 Jun 64

After a shift of Bacillus subtilis from aerobic to anaerobic growth conditions, nitrate ammonification and various fermentative processes replace oxygen-dependent respiration. Cell-free extracts prepared from wild-type B. subtilis and from mutants of the regulatory loci fnr and resDE grown under aerobic and various anaerobic conditions were compared by two-dimensional gel electrophoresis. Proteins involved in the adaptation process were identified by their N-terminal sequence. Induction of cytoplasmic lactate dehydrogenase (LctE) synthesis under anaerobic fermentative conditions was dependent on fnr and resDE. Anaerobic nitrate repression of LctE formation required fnr-mediated expression of narGHJI, encoding respiratory nitrate reductase. Anaerobic induction of the flavohaemoglobin Hmp required resDE and nitrite. The general anaerobic induction of ywfl, encoding a protein of unknown function, was modulated by resDE and fnr. The ywfl gene shares its upstream region with the pta gene, encoding the fermentative enzyme acetyl-CoA:orthophosphate acetyltransferase. Anaerobic repression of the synthesis of a potential membrane-associated NADH dehydrogenase (YjlD, Ndh), and anaerobic induction of fructose-1,6-bisphosphate aldolase (FbaA) and dehydrolipoamide dehydrogenase (PhdD, Lpd) formation, did not require fnr or resDE participation. Synthesis of glycerol kinase (GlpK) was decreased under anaerobic conditions. Finally, the effect of anaerobic stress induced by the immediate shift from aerobic to strictly anaerobic conditions was analysed. The induction of various systems for the utilization of alternative carbon sources such as inositol (IoIA, IoIG, IoIH, IoII), melibiose (MeIA) and 6-phospho-alpha-glucosides (GIvA) indicated a catabolite-response-like stress reaction.
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PMID:Changes in protein synthesis during the adaptation of Bacillus subtilis to anaerobic growth conditions. 1065 56

The synthesis of the enzymes constituting the electron transport chain of Escherichia coli is controlled by electron acceptors in order to achieve high ATP yields and high metabolic rates as well. High ATP yields (or efficiency) are obtained by the use of electron acceptors for respiration which allow high ATP yields, preferentially O2, and nitrate in the absence of O2. The rate of metabolism is adjusted by use of respiratory isoenzymes which differ in the rate and the efficiency of energy conservation, such as the non-coupling NADH dehydrogenase II (ndh gene) and the coupling NADH dehydrogenase I (nuo genes). By combination of the contrary principles (rate versus efficiency), growth is optimized for growth yields and rates. One of the major transcriptional regulators controlling the switch from aerobic to anaerobic respiration is FNR (fumarate nitrate reductase regulator). FNR is located in the cytoplasm and contains a [4Fe-4S] cluster in the active (anaerobic) state. By reaction with O2 the cluster is converted to a [2Fe-2S] cluster and finally to apoFNR. O2 diffuses into the cytoplasm even at very low O2-tensions (1 microM) where it inactivates [4Fe-4S] x FNR. The formation of [4Fe-4S] x FNR from apoFNR can use glutathione as a reducing agent in vitro. This process could also be important for the reductive activation of FNR in vivo. A model for the control of the functional state of FNR by O2 and glutathione is discussed. According to this model the functional state of FNR is determined by a (rapid) inactivation of FNR by O2, and a slow (constant) reactivation with glutathione as the reducing agent.
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PMID:Control of FNR function of Escherichia coli by O2 and reducing conditions. 1193 57

The halotolerant alkaliphilic methanotroph Methylomicrobium buryatense 5B is capable of growth at high methanol concentrations (up to 1.75 M). At optimal values of pH and salinity (pH 9.5 and 0.75% NaCl), the maximum growth rate on 0.25 M methanol (0.2 h-1) was twice as high as on methane (0.1 h-1). The maximum growth rate increased with increasing medium salinity and was lower at neutral than at alkaline pH. The growth of the bacterium on methanol was accompanied by a reduction in the degree of development of intracytoplasmic membranes, the appearance of glycogen granules in cells, and the accumulation of formaldehyde, formate, and an extracellular glycoprotein at concentrations of 1.2 mM, 8 mM, and 2.63 g/l, respectively. The glycoprotein was found to contain 23% protein and 77% carbohydrates, the latter being dominated by glucose, mannose, and aminosugars. The major amino acids were glutamate, aspartate, glycine, valine, and isoleucine. The glycoprotein content rose to 5 g/l when the concentration of potassium nitrate in the medium was augmented tenfold. The activities of sucrose-6-phosphate synthase, glycogen synthase, and NADH dehydrogenase in methanol-grown cells were higher than in methane-grown cells. The data obtained suggest that the high methanol tolerance of M. buryatense 5B is due to the utilization of formaldehyde for the synthesis of sucrose, glycogen, and the glycoprotein and to the oxidation of excess reducing equivalents through the respiratory chain.
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PMID:[Physiological, biochemical, and cytological characteristics of a halotolerant and alkalitolerant methanotroph grown on methanol]. 1244 24

The Escherichia coli ndh gene encodes NADH dehydrogenase II, a primary dehydrogenase used during aerobic and nitrate respiration. The anaerobic transcription factor FNR represses ndh expression by binding at two sites centred at -94.5 and -50.5. In vivo transcription studies using promoter fusions with 5' deletions confirmed that both FNR sites are required for maximum repression under anaerobic conditions. The histone-like protein Fis binds to three sites [centred at -123 (Fis I), -72, (Fis II) and +51 (Fis III)] in the ndh promoter. Using ndh : : lacZ promoter fusions carrying 5' deletions, or replacement mutations it is shown that Fis III is a repressing site and that Fis I and II are activating sites, with the greatest contribution from Fis II. Deletion of the C-terminal domain of the RNA polymerase alpha-subunit abolished Fis-mediated activation of ndh expression, suggesting that ndh has a Class I Fis-activated promoter. In accordance with the established pattern of Fis synthesis, ndh transcription was greatest during exponential growth. Thus, it is suggested that Fis enhances ndh expression during periods of rapid growth, by acting as a Class I activator, and that the binding of tandem FNR dimers represses ndh expression by preventing interaction of the RNA polymerase alpha-subunit with DNA and Fis.
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PMID:Regulation of ndh expression in Escherichia coli by Fis. 1476 19


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