Respiratory Metabolism in Hyperthermophilic Organisms: Hydrogenases, Sulfur Reductases, and Electron Transport Factors that Function at Temperatures Exceeding 100°C

Maier, Robert J.

doi:10.1016/s0065-3233(08)60361-7

Cited by 10 publications

(10 citation statements)

References 172 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Among the identified ORFs are ones postulated to be genes for heme biosynthetic pathway enzymes. This is in contrast to other well‐characterized hyperthermophiles such as the Archaeon Pyrococcus furiosus which lack heme‐containing respiratory chains [3,4].…”

Section: Introductioncontrasting

confidence: 59%

Expression and characterization of the terminal heme synthetic enzymes from the hyperthermophileAquifex aeolicus

Wang

Dailey

2001

FEMS Microbiology Letters

View full text Add to dashboard Cite

The terminal two heme biosynthetic pathway enzymes, protoporphyrinogen oxidase and ferrochelatase, of the hyperthermophilic bacterium Aquifex aeolicus have been expressed in Escherichia coli, purified to homogeneity, and biochemically characterized. Ferrochelatase and protoporphyrinogen oxidase of this organism are both monomeric, as was found for the corresponding enzymes of Bacillus subtilis. However, unlike the B. subtilis proteins, both A. aeolicus enzymes are membrane-associated. Both proteins have temperature optima over 60 degrees C. This is the first demonstration of functional heme biosynthetic enzymes in an extreme thermophilic bacterium.

show abstract

Section: Introductioncontrasting

confidence: 59%

Expression and characterization of the terminal heme synthetic enzymes from the hyperthermophileAquifex aeolicus

Wang

Dailey

2001

FEMS Microbiology Letters

View full text Add to dashboard Cite

show abstract

“…The cytochrome c (30 kDa) is approximately twice as large as that of P. brockii . It should be pointed out that among hyperthermophiles, c ‐type cytochromes have been detected only in species of Pyrodictium [22, 105]. No quinone has been detected in the H 2 :sulfur oxidoreductase or in the membrane fraction of P. abyssi isolate TAG11.…”

Section: Sulfur Respiration In Hyperthermophilic Archaeamentioning

confidence: 99%

“…In the membranes of P. brockii , a hydrogenase, a quinone, and a cytochrome c have been identified as part of a proposed respiratory electron transport chain [105–107]. The hydrogenase has been purified and found to be of the Ni/Fe‐type and to consist of two subunits (66–68 kDa and 45 kDa) [106].…”

Section: Sulfur Respiration In Hyperthermophilic Archaeamentioning

confidence: 99%

See 1 more Smart Citation

Anaerobic respiration with elemental sulfur and with disulfides

Hedderich¹,

Klimmek²,

Kröger³

et al. 1998

FEMS Microbiol Rev

250

149

View full text Add to dashboard Cite

Anaerobic respiration with elemental sulfur/polysulfide or organic disulfides is performed by several bacteria and archaea, but has only been investigated in a few organisms in detail. The electron transport chain that catalyzes polysulfide reduction in the Gram‐negative bacterium Wolinella succinogenes consists of a dehydrogenase (formate dehydrogenase or hydrogenase) and polysulfide reductase. The enzymes are integrated in the cytoplasmic membrane with the catalytic subunits exposed to the periplasm. The mechanism of electron transfer from formate dehydrogenase or hydrogenase to polysulfide reductase is discussed. The catalytic subunit of polysulfide reductase belongs to the family of molybdopterin‐dinucleotide‐containing oxidoreductases. From the hyperthermophilic archaeon Pyrodictium abyssi isolate TAG11 an integral membrane complex has been isolated which catalyzes the reduction of sulfur with H2 as electron donor. This enzyme complex, which is composed of a hydrogenase and a sulfur reductase, contains heme groups and several iron‐sulfur clusters, but does not contain molybdenum or tungsten. In methanogenic archaea, the heterodisulfide of coenzyme M and coenzyme B is the terminal electron acceptor of the respiratory chain. In methanogens belonging to the order Methanosarcinales, this respiratory chain is composed of a dehydrogenase, the membrane‐soluble electron carrier methanophenazine, and heterodisulfide reductase. The catalytic subunit of heterodisulfide reductase contains only iron‐sulfur clusters. An iron‐sulfur cluster may directly be involved in the reduction of the disulfide substrate.

show abstract

“…Elemental sulfur or polysulfides serve as the terminal electron acceptor for sulfur respiration among several crenarchaeotes [for a review, see Maier (1996)]. The growth of many heterotrophic hyperthermophiles including Pyrococcus furiosus and Thermotoga maritima is enhanced by the reduction of sulfanes, but the reason for this has been elusive.…”

Section: Introductionmentioning

confidence: 99%

Membrane-associated redox activities in Thermotoga neapolitana

Käslin

Childers

Noll

1998

Archives of Microbiology

View full text Add to dashboard Cite

Elemental sulfur reduction by the hyperthermophilic bacterium Thermotoga neapolitana provides an alternative to hydrogen evolution during fermentation. Electrons are transferred from reduced cofactors (ferredoxin and NADH) to sulfur by a series of unknown steps. One enzyme that may be involved is an NADH:methyl viologen oxidoreductase (NMOR), an activity that in other fermenting organisms is associated with NADH:ferredoxin oxidoreductase. We found that 83% of NMOR activity was contained in the pellet fraction of cell extracts subjected to ultracentrifugation. This pellet fraction, presumably containing cell membranes, was required for electron transfer to NAD+ from ferredoxin-dependent pyruvate oxidation. However, the NMOR activity in this fraction used neither Thermotoga nor clostridial ferredoxins as substrates. NMOR activity was also detected in aerobically prepared vesicles. By comparison with ATPase activities, NMOR was found primarily on the cytoplasmic face of these vesicles. During these studies, an extracytoplasmic hydrogenase activity was discovered. In contrast to the soluble hydrogenase, this hydrogenase activity was completely inhibited when intact cells were treated with cupric chloride and was present on the extracytoplasmic face of vescides. In contrast to a soluble hydrogenase reported in Thermotoga maritima, this activity was air-stable and was inhibited by low concentrations of nitrite.

show abstract

Respiratory Metabolism in Hyperthermophilic Organisms: Hydrogenases, Sulfur Reductases, and Electron Transport Factors that Function at Temperatures Exceeding 100°C

Cited by 10 publications

References 172 publications

Expression and characterization of the terminal heme synthetic enzymes from the hyperthermophileAquifex aeolicus

Expression and characterization of the terminal heme synthetic enzymes from the hyperthermophileAquifex aeolicus

Anaerobic respiration with elemental sulfur and with disulfides

Membrane-associated redox activities in Thermotoga neapolitana

Contact Info

Product

Resources

About