Organization of the respiratory chain of Neisseria meningitidis

2006 ◽  
Vol 34 (1) ◽  
pp. 139-142 ◽  
Author(s):  
M. Deeudom ◽  
J. Rock ◽  
J. Moir
Keyword(s):  
Nitric Oxide ◽  
Neisseria Meningitidis ◽  
Cytochrome Oxidase ◽  
Nitrite Reductase ◽  
Electron Flow ◽  
Bc1 Complex ◽  
Nitric Oxide Reductase ◽  
Intact Cells ◽  
Nitrite Reductase Gene ◽  
Reductase Gene

The ability of Neisseria meningitidis to utilize both oxygen and nitrogen oxides as respiratory substrates allows it to thrive in the diverse environment of the human host. Genome analysis highlighted genes encoding a cbb3 cytochrome oxidase, the aniA nitrite reductase gene and the norB nitric oxide reductase gene. In the present study, we used myxothiazol as an inhibitor of the bc1 complex in intact cells and demonstrated that electron flow to nitrite reductase and the cytochrome oxidase, but not NO reductase, passes via the cytochrome bc1 complex. UV–visible spectrophotometry of intact cells demonstrated that oxygen oxidizes c-type and b-type cytochromes. Oxidation of cytochromes by nitrite was only seen in microaerobically precultured whole cells, and the predominant oxidizable cytochromes were b-type. These are likely to be associated with the oxidation of a b-haem-containing nitric oxide reductase. Nitrite inhibits the oxidation of cytochromes by oxygen in a nitrite reductase-independent manner, indicating that nitrite may inhibit oxidase activity directly, as well as via the intermediate of denitrification, nitric oxide.

Microaerobic denitrification in Neisseria meningitidis

2005 ◽  
Vol 33 (1) ◽  
pp. 134-136 ◽  
Author(s):  
J.D. Rock ◽  
J.W.B. Moir
Keyword(s):  
Neisseria Meningitidis ◽  
Respiratory Chain ◽  
Growth Conditions ◽  
Nitric Oxide Reductase ◽  
Genome Sequences ◽  
Course Of Disease ◽  
Nitrite Reductase Gene ◽  
Reductase Gene ◽  
Microaerobic Conditions ◽  
Limited Oxygen

The major aetiological agent of human bacterial meningitis is Neisseria meningitidis. During the course of disease and host colonization, the bacterium has to withstand limited oxygen availability. Nitrogen oxide and nitrogen oxyanions are thought to be present, which may constitute an alternative sink for electrons from the N. meningitidis respiratory chain. A partial denitrification pathway is encoded by the aniA nitrite reductase gene and the norB nitric oxide reductase gene. Analysis of the completed genome sequences of two N. meningitidis strains is used to generate a model for the membrane-associated respiratory chain of this organism. Analysis of aniA expression indicates it to be controlled primarily by oxygen and secondarily by nitrite. The ability of N. meningitidis to denitrify relies on microaerobic growth conditions. Here we show that under microaerobic conditions nitrite supplements oxygen as an alternative respiratory substrate.

Separation of soluble denitrifying enzymes and cytochromes from Pseudomonas perfectomarinus

1973 ◽  
Vol 19 (7) ◽  
pp. 861-872 ◽  
Author(s):  
C. D. Cox Jr. ◽  
W. J. Payne
Keyword(s):  
Nitric Oxide ◽  
Electron Donor ◽  
Nitrite Reductase ◽  
Reductase Activity ◽  
Electron Flow ◽  
Deae Cellulose ◽  
The Other ◽  
Nitric Oxide Reductase ◽  
Effective Electron ◽  
Nitrite Reductase Activity

Nitrite and nitric oxide reductases were found soluble in extracts of Pseudomonas perfectomarinus cultured anaerobically at the expense of nitrate and ruptured with the French pressure cell. Malic enzyme, transhydrogenase, and flavin reductase that provided electron flow for these reductases were soluble as well. Nitrous oxide reductase remained particle-bound. Exogenous NADH was a poor electron donor for crude extracts, but a combination of malate, NADP, and NAD served well in the reduction of nitrite and nitric oxide. Nitrite reductase activity lost on dialysis of crude extract was restored by addition of this combination. Addition of free flavins was required for reduction of nitrite and nitric oxide. A nitrite reductase complex was separated from the nitric oxide reductase by gel filtration and DEAE-cellulose chromatography. NADH was an effective electron donor for this system with flavins provided as well. A c-type cytochrome with a split-α peak (perhaps associated with a d type) and two additional c-type cytochromes were separated from the nitrite reductase fraction. One of the latter (RI) emerged oxidized, the other (RII) reduced. Only nitric oxide oxidized RII. When these cytochromes were added to reaction mixtures containing nitrite reductase, activity was increased most by the split-α fraction. After reduction with dithionite, the absorption spectrum of the split-α cytochrome was returned to the oxidized spectrum by addition of nitrite but not the other oxides. A significant amount of a c-type cytochrome remained bound to the nitric oxide reductase fraction. A combination of malic acid, NAD, and NADP was more effective than NADH as electron donor for this system with free flavins provided as well. Addition of RI increased the rate of nitric oxide reduction by this fraction.

Molecular Cloning and Characterization of Nitrite Reductase Gene from Sugarbeet

2011 ◽  
Vol 37 (8) ◽  
pp. 1406-1414
Author(s):  
Xiao-Yan SHI ◽  
Yan-Da ZENG ◽  
Shi-Long LI ◽  
Yu-Bo WANG ◽  
Feng-Ming MA ◽  
...  
Keyword(s):  
Molecular Cloning ◽  
Nitrite Reductase ◽  
Nitrite Reductase Gene ◽  
Reductase Gene

scholarly journals A novel nitrite reductase gene from the cyanobacterium Plectonema boryanum.

1995 ◽  
Vol 177 (21) ◽  
pp. 6137-6143 ◽  
Author(s):  
I Suzuki ◽  
H Kikuchi ◽  
S Nakanishi ◽  
Y Fujita ◽  
T Sugiyama ◽  
...  
Keyword(s):  
Nitrite Reductase ◽  
Plectonema Boryanum ◽  
Nitrite Reductase Gene ◽  
Reductase Gene

scholarly journals Denitrification Activity and Relevant Bacteria Revealed by Nitrite Reductase Gene Fragments in Soil of Temperate Mixed Forest

2009 ◽  
Vol 24 (1) ◽  
pp. 76
Author(s):  
Chie Katsuyama ◽  
Naho Kondo ◽  
Yuichi Suwa ◽  
Takao Yamagishi ◽  
Masayuki Itoh ◽  
...  
Keyword(s):  
Nitrite Reductase ◽  
Mixed Forest ◽  
Nitrite Reductase Gene ◽  
Reductase Gene ◽  
Denitrification Activity ◽  
Temperate Mixed Forest

Agricultural soil denitrifiers possess extensive nitrite reductase gene diversity

2017 ◽  
Vol 19 (3) ◽  
pp. 1189-1208 ◽  
Author(s):  
Sara Coyotzi ◽  
Andrew C. Doxey ◽  
Ian D. Clark ◽  
David R. Lapen ◽  
Philippe Van Cappellen ◽  
...  
Keyword(s):  
Nitrite Reductase ◽  
Agricultural Soil ◽  
Gene Diversity ◽  
Nitrite Reductase Gene ◽  
Reductase Gene

scholarly journals Functional interactions between nitrite reductase and nitric oxide reductase from Paracoccus denitrificans

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ingrid Albertsson ◽  
Johannes Sjöholm ◽  
Josy ter Beek ◽  
Nicholas J. Watmough ◽  
Jerker Widengren ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitrite Reductase ◽  
Paracoccus Denitrificans ◽  
Affinity Constant ◽  
Nitric Oxide Reductase ◽  
Terminal Electron Acceptor ◽  
Model Soil ◽  
Transient Interactions ◽  
Electron Donation

AbstractDenitrification is a microbial pathway that constitutes an important part of the nitrogen cycle on earth. Denitrifying organisms use nitrate as a terminal electron acceptor and reduce it stepwise to nitrogen gas, a process that produces the toxic nitric oxide (NO) molecule as an intermediate. In this work, we have investigated the possible functional interaction between the enzyme that produces NO; the cd1 nitrite reductase (cd1NiR) and the enzyme that reduces NO; the c-type nitric oxide reductase (cNOR), from the model soil bacterium P. denitrificans. Such an interaction was observed previously between purified components from P. aeruginosa and could help channeling the NO (directly from the site of formation to the side of reduction), in order to protect the cell from this toxic intermediate. We find that electron donation to cNOR is inhibited in the presence of cd1NiR, presumably because cd1NiR binds cNOR at the same location as the electron donor. We further find that the presence of cNOR influences the dimerization of cd1NiR. Overall, although we find no evidence for a high-affinity, constant interaction between the two enzymes, our data supports transient interactions between cd1NiR and cNOR that influence enzymatic properties of cNOR and oligomerization properties of cd1NiR. We speculate that this could be of particular importance in vivo during metabolic switches between aerobic and denitrifying conditions.

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