A New Paradigm for Electron Transfer through Escherichia coli Nitrate Reductase A

Biochemistry ◽  
2014 ◽  
Vol 53 (28) ◽  
pp. 4549-4556 ◽  
Author(s):  
Justin G. Fedor ◽  
Richard A. Rothery ◽  
Joel H. Weiner
Keyword(s):  
Escherichia Coli ◽  
Electron Transfer ◽  
Nitrate Reductase ◽  
New Paradigm

scholarly journals NapGH components of the periplasmic nitrate reductase of Escherichia coli K-12: location, topology and physiological roles in quinol oxidation and redox balancing

2004 ◽  
Vol 379 (1) ◽  
pp. 47-55 ◽  
Author(s):  
T. Harma C. BRONDIJK ◽  
Arjaree NILAVONGSE ◽  
Nina FILENKO ◽  
David J. RICHARDSON ◽  
Jeffrey A. COLE
Keyword(s):  
Escherichia Coli ◽  
Electron Transfer ◽  
Nitrate Reductase ◽  
Nitrate Reduction ◽  
Residual Rate ◽  
Periplasmic Nitrate Reductase ◽  
Essential Components ◽  
K 12

Nap (periplasmic nitrate reductase) operons of many bacteria include four common, essential components, napD, napA, napB and napC (or a homologue of napC). In Escherichia coli there are three additional genes, napF, napG and napH, none of which are essential for Nap activity. We now show that deletion of either napG or napH almost abolished Nap-dependent nitrate reduction by strains defective in naphthoquinone synthesis. The residual rate of nitrate reduction (approx. 1% of that of napG+H+ strains) is sufficient to replace fumarate reduction in a redox-balancing role during growth by glucose fermentation. Western blotting combined with β-galactosidase and alkaline phosphatase fusion experiments established that NapH is an integral membrane protein with four transmembrane helices. Both the N- and C-termini as well as the two non-haem iron–sulphur centres are located in the cytoplasm. An N-terminal twin arginine motif was shown to be essential for NapG function, consistent with the expectation that NapG is secreted into the periplasm by the twin arginine translocation pathway. A bacterial two-hybrid system was used to show that NapH interacts, presumably on the cytoplasmic side of, or within, the membrane, with NapC. As expected for a periplasmic protein, no NapG interactions with NapC or NapH were detected in the cytoplasm. An in vitro quinol dehydrogenase assay was developed to show that both NapG and NapH are essential for rapid electron transfer from menadiol to the terminal NapAB complex. These new in vivo and in vitro results establish that NapG and NapH form a quinol dehydrogenase that couples electron transfer from the high midpoint redox potential ubiquinone–ubiquinol couple via NapC and NapB to NapA.

scholarly journals Structural genes for nitrate-inducible formate dehydrogenase in Escherichia coli K-12.

Genetics ◽  
1990 ◽  
Vol 125 (4) ◽  
pp. 691-702 ◽  
Author(s):  
B L Berg ◽  
V Stewart
Keyword(s):  
Escherichia Coli ◽  
Nitrate Reductase ◽  
Formate Dehydrogenase ◽  
Recombinant Dna ◽  
Structural Genes ◽  
Respiratory Pathway ◽  
E Coli ◽  
Formate Oxidation ◽  
Operon Expression ◽  
K 12

Abstract Formate oxidation coupled to nitrate reduction constitutes a major anaerobic respiratory pathway in Escherichia coli. This respiratory chain consists of formate dehydrogenase-N, quinone, and nitrate reductase. We have isolated a recombinant DNA clone that likely contains the structural genes, fdnGHI, for the three subunits of formate dehydrogenase-N. The fdnGHI clone produced proteins of 110, 32 and 20 kDa which correspond to the subunit sizes of purified formate dehydrogenase-N. Our analysis indicates that fdnGHI is organized as an operon. We mapped the fdn operon to 32 min on the E. coli genetic map, close to the genes for cryptic nitrate reductase (encoded by the narZ operon). Expression of phi(fdnG-lacZ) operon fusions was induced by anaerobiosis and nitrate. This induction required fnr+ and narL+, two regulatory genes whose products are also required for the anaerobic, nitrate-inducible activation of the nitrate reductase structural gene operon, narGHJI. We conclude that regulation of fdnGHI and narGHJI expression is mediated through common pathways.

scholarly journals Kinetics of electron transfer from NADH to the Escherichia coli nitric oxide reductase flavorubredoxin

FEBS Journal ◽  
2006 ◽  
Vol 274 (3) ◽  
pp. 677-686 ◽  
Author(s):  
João B. Vicente ◽  
Francesca M. Scandurra ◽  
João V. Rodrigues ◽  
Maurizio Brunori ◽  
Paolo Sarti ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Escherichia Coli ◽  
Electron Transfer ◽  
Nitric Oxide Reductase ◽  
Kinetics Of

scholarly journals Using Structure-Function Relationships to Understand the Mechanism of Phenazine Mediated Extracellular Electron Transfer in Escherichia coli

iScience ◽  
2021 ◽  
pp. 103033
Author(s):  
Zayn Rhodes ◽  
Olja Simoska ◽  
Ashwini Dantanarayana ◽  
Keith J. Stevenson ◽  
Shelley D. Minteer
Keyword(s):  
Escherichia Coli ◽  
Electron Transfer ◽  
Structure Function ◽  
Extracellular Electron Transfer
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