Publications by authors named "Meriem Merrouch"

Enhancer binding proteins (EBPs) are key players of σ -regulation that control transcription in response to environmental signals. In the anaerobic microorganism Desulfovibrio vulgaris Hildenborough (DvH), orp operons have been previously shown to be coregulated by σ -RNA polymerase, the integration host factor IHF and a cognate EBP, OrpR. In this study, ChIP-seq experiments indicated that the OrpR regulon consists of only the two divergent orp operons.

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Ni-Fe CO-dehydrogenases (CODHs) catalyze the conversion between CO and CO using a chain of Fe-S clusters to mediate long-range electron transfer. One of these clusters, the D-cluster, is surface-exposed and serves to transfer electrons between CODH and external redox partners. These enzymes tend to be extremely O-sensitive and are always manipulated under strictly anaerobic conditions.

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The nickel-dependent carbon monoxide dehydrogenase (CODH) employs a unique heterometallic nickel-iron-sulfur cluster, termed the C-cluster, to catalyze the interconversion of CO and CO Like other complex metalloenzymes, CODH requires dedicated assembly machinery to form the fully intact and functional C-cluster. In particular, nickel incorporation into the C-cluster depends on the maturation factor CooC; however, the mechanism of nickel insertion remains poorly understood. Here, we compare X-ray structures (1.

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The C-cluster of the enzyme carbon monoxide dehydrogenase (CODH) is a structurally distinctive Ni-Fe-S cluster employed to catalyze the reduction of CO to CO as part of the Wood-Ljungdahl carbon fixation pathway. Using X-ray crystallography, we have observed unprecedented conformational dynamics in the C-cluster of the CODH from , providing the first view of an oxidized state of the cluster. Combined with supporting spectroscopic data, our structures reveal that this novel, oxidized cluster arrangement plays a role in avoiding irreversible oxidative degradation at the C-cluster.

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Nickel-containing enzymes are diverse in terms of function and active site structure. In many cases, the biosynthesis of the active site depends on accessory proteins which transport and insert the Ni ion. We review and discuss the literature related to the maturation of carbon monoxide dehydrogenases (CODH) which bear a nickel-containing active site consisting of a [Ni-4Fe-4S] center called the C-cluster.

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CO dehydrogenases (CODHs) catalyse the reversible conversion between CO and CO . Genomic analysis indicated that the metabolic functions of CODHs vary. The genome of Carboxydothermus hydrogenoformans encodes five CODHs (CODH-I-V), of which CODH-IV is found in a gene cluster near a peroxide-reducing enzyme.

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Ni-containing CO dehydrogenases (CODHs) are very efficient metalloenzymes that catalyze the conversion between CO2 and CO. They are a source of inspiration for designing CO2-reduction catalysts and can also find direct use in biotechnology. They are deemed extremely sensitive to O2, but very little is known about this aspect of their reactivity.

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A novel anaerobic bacterial strain, ST07-YET, was isolated from a carbonate chimney of the Prony Hydrothermal Field (PHF) in New Caledonia. Cells were Gram-stain-positive, straight rods (0.7-0.

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