Biosynthesis of vitamin K (menaquinone) in bacteria.

Bentley, Ronald; Meganathan, R.

doi:10.1128/mmbr.46.3.241-280.1982

Cited by 252 publications

(145 citation statements)

References 128 publications

(183 reference statements)

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“…This synthase catalyzes the formal back reaction of the hydrolase, namely formation of the aromatic ring in naphthoate synthesis from the precursor o-succinylbenzoyl-CoA. This reaction plays a role in anaerobic menaquinone biosynthesis (Bentley and Meganathan, 1982).…”

Section: Resultsmentioning

confidence: 99%

Genes coding for the benzoyl‐CoA pathway of anaerobic aromatic metabolism in the bacterium Thauera aromatica

Breese

Boll

Alt-Mörbe

et al. 1998

European Journal of Biochemistry

107

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Many aromatic compounds are anaerobically oxidized to CO 2 via benzoyl-CoA as the common aromatic intermediate. In Thauera aromatica, the central benzoyl-CoA pathway comprises the ATP-driven two-electron reduction of the benzene ring; this reaction uses a ferredoxin as electron donor and is catalyzed by benzoyl-CoA reductase. The first intermediate, cyclohex-1,5-diene-1-carboxyl-CoA, is subsequently hydrated by dienoyl-CoA hydratase to 6-hydroxycyclohex-1-ene-1-carboxyl-CoA. Formation of the main product produced by cell extracts, 3-hydroxypimelyl-CoA, requires at least two further steps; the oxidation of a hydroxyl group and the hydrolytic carbon ring cleavage of a CoA-activated β-oxoacid. In addition, enoyl-CoA hydratase may come into play. A cluster of eight adjacent genes, which are transcribed in the same direction and may form an operon, was found in this bacterium. The cluster codes for proven and postulated enzymes of the benzoyl-CoA pathway. The genes for the enzymes code for ferredoxin, four subunits of benzoyl-CoA reductase, dienoyl-CoA hydratase, 6-hydroxycyclohex-1-ene-1-carboxyl-CoA dehydrogenase (NAD ϩ ), and the ring hydrolyzing enzyme. The deduced amino acid sequences of these proteins were 35Ϫ86% similar to the corresponding sequences found in Rhodopseudomonas palustris. Benzoyl-CoA reductase subunits exhibit distinct similarities with 2-hydroxyglutarylCoA dehydratase and its ATP-hydrolysing activase protein of Acidaminococcus fermentans as well as with open reading frames of unknown function in other bacteria. Conversion of benzoyl-CoA to 3-hydroxypimelyl-CoA can be explained by a minimal model of the benzoyl-CoA pathway assuming the four enzymes whose genes were characterized and an additional enoyl-CoA hydratase. In R. palustris the dienoyl-CoA hydratase gene is lacking suggesting the operation of a modified benzoyl-CoA pathway with cyclohex-1-ene-1-carboxyl-CoA as intermediate.Keywords : benzoyl-CoA pathway ; benzoyl-CoA reductase; dienoyl-CoA hydratase; 3-hydroxypimelylCoA; 2-hydroxyglutaryl-CoA dehydratase.Aerobic aromatic metabolism is well known for the extensive use of molecular oxygen. Monooxygenases and dioxygenases are essential for the hydroxylation and for the cleavage of aromatic ring structures. Anaerobic aromatic metabolism necessarily requires a quite different strategy. Essential is the replacement of oxygen-dependent steps by a set of alternative reactions and the formation of different central intermediates, i.e. a completely different solution to overcome the energy barrier of the aromatic ring systems. Notably, in anaerobic pathways, the aro-

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Section: Resultsmentioning

confidence: 99%

Genes coding for the benzoyl‐CoA pathway of anaerobic aromatic metabolism in the bacterium Thauera aromatica

Breese

Boll

Alt-Mörbe

et al. 1998

European Journal of Biochemistry

107

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“…Vitamin K 1 is found in dietary and medicinal substances (phytonadione or phylloquinone); vitamin K 2 is a series of compounds produced by bacteria in the intestinal tract (menaquinones). 3,4 The role of all vitamin K compounds is an essential cofactor in the carboxylation of glutamate residues into ␥carboxyglutamate in the later stages of protein biosynthesis of many proteins, such as vitamin K-dependent clotting factors (VII, IX, X, and II) in the liver. 5,6 Vitamin K is oxidized in this reaction to the epoxide form (KO) and must be returned to the active hydroquinone form (KH 2 ) in a two-step reduction reaction to continue the generation of clotting factors.…”

Section: Discussionmentioning

confidence: 99%

Impaired Warfarin Response Secondary to High‐Dose Vitamin K1 for Rapid Anticoagulation Reversal: Case Series and Literature Review

2004

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The literature suggests that unresponsiveness to warfarin can continue for 1 week or longer after administration of high-dose vitamin K1 10 mg or greater; however, there is a lack of supporting data to define the duration and clinical consequences of impaired warfarin response with high doses of vitamin K1. This case series describes four patients receiving indefinite warfarin therapy who received high and, in most cases, repeated doses of vitamin K1 for urgent reversal of therapeutic anticoagulation for an invasive procedure or surgery. The patients displayed impaired warfarin response for 11 days-3.5 weeks after administration of vitamin K1 10-40 mg. The associated financial burden for the patients was substantial. We reviewed the literature to examine the mechanism of impaired warfarin response, and the clinical efficacy, safety, and appropriateness of vitamin K1 and fresh-frozen plasma in urgent reversal of anticoagulation.

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“…This operon configuration generates two mRNAs, the polycistronic menE-menC-yktD-MW1731 and the MW1733 mRNA, which completely overlaps the polycistronic mRNA in the region between menC and ytkD. Therefore, the expres- The synthesis of menaquinone, a component of the electron-transport system (Bentley & Meganathan, 1982), illustrates well how the noncontiguous operon genetic arrangement may play a key role in the capacity of pathogenic bacteria to grow inside cells.…”

Section: The Excludon Conceptmentioning

confidence: 94%

Advances in bacterial transcriptome understanding: From overlapping transcription to the excludon concept

Toledo‐Arana

Lasa

2020

Molecular Microbiology

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In the last decade, the implementation of high‐throughput methods for RNA profiling has uncovered that a large part of the bacterial genome is transcribed well beyond the boundaries of known genes. Therefore, the transcriptional space of a gene very often invades the space of a neighbouring gene, creating large regions of overlapping transcription. The biological significance of these findings was initially regarded with scepticism. However, mounting evidence suggests that overlapping transcription between neighbouring genes conforms to regulatory purposes and provides new strategies for coordinating bacterial gene expression. In this MicroReview, considering the discoveries made in a pioneering transcriptome analysis performed on Listeria monocytogenes as a starting point, we discuss the progress in understanding the biological meaning of overlapping transcription that has given rise to the excludon concept. We also discuss new conditional transcriptional termination events that create antisense RNAs depending on the metabolite concentrations and new genomic arrangements, known as noncontiguous operons, which contain an interspersed gene that is transcribed in the opposite direction to the rest of the operon.

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Biosynthesis of vitamin K (menaquinone) in bacteria.

Cited by 252 publications

References 128 publications

Genes coding for the benzoyl‐CoA pathway of anaerobic aromatic metabolism in the bacterium Thauera aromatica

Genes coding for the benzoyl‐CoA pathway of anaerobic aromatic metabolism in the bacterium Thauera aromatica

Impaired Warfarin Response Secondary to High‐Dose Vitamin K1 for Rapid Anticoagulation Reversal: Case Series and Literature Review

Advances in bacterial transcriptome understanding: From overlapping transcription to the excludon concept

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