| syntrophic degradation of cadaverine by a defined methanogenic coculture. | a novel, strictly anaerobic, cadaverine-oxidizing, defined coculture was isolated from an anoxic freshwater sediment sample. the coculture oxidized cadaverine (1,5-diaminopentane) with sulfate as the electron acceptor. the sulfate-reducing partner could be replaced by a hydrogenotrophic methanogenic partner. the defined coculture fermented cadaverine to acetate, butyrate, and glutarate plus sulfide or methane. the key enzymes involved in cadaverine degradation were identified in cell extracts. a ... | 2009 | 19465531 |
| a 49 kda microtubule cross-linking protein from artemia franciscana is a coenzyme a-transferase. | embryos and larvae of the brine shrimp, artemia franciscana, were shown previously to possess a protein, now termed p49, which cross-links microtubules in vitro. molecular characteristics of p49 were described, but the protein's identity and its role in the cell were not determined. degenerate oligonucleotide primers designed on the basis of peptide sequence obtained by edman degradation during this study were used to generate p49 cdnas by rt-pcr and these were cloned and sequenced. comparison w ... | 2003 | 14653822 |
| the possible influence of micro-organisms and putrefaction in the production of ghb in post-mortem biological fluid. | in recent years, the post-mortem production of the drug of abuse gamma-hydroxybutyric acid (ghb) in biological fluids (e.g. blood and urine) has caused various interpretative problems for toxicologists. previously, other researchers have shown certain microbial species (pseudomonas spp. and clostridium aminobutyricum) possess the necessary enzymes to convert gaba to ghb. a preliminary investigation involving putrefied post-mortem blood indicated there was no observed relationship between "endoge ... | 2004 | 15040914 |
| crystal structure of 4-hydroxybutyryl-coa dehydratase: radical catalysis involving a [4fe-4s] cluster and flavin. | dehydratases catalyze the breakage of a carbon-oxygen bond leading to unsaturated products via the elimination of water. the 1.6-a resolution crystal structure of 4-hydroxybutyryl-coa dehydratase from the gamma-aminobutyrate-fermenting clostridium aminobutyricum represents a new class of dehydratases with an unprecedented active site architecture. a [4fe-4s](2+) cluster, coordinated by three cysteine and one histidine residues, is located 7 a from the re-side of a flavin adenine dinucleotide (fa ... | 2004 | 15496473 |
| synthesis of (13)c-labeled gamma-hydroxybutyrates for epr studies with 4-hydroxybutyryl-coa dehydratase. | 4-hydroxybutyryl-coa dehydratase from clostridium aminobutyricum catalyses the reversible dehydration of its substrate 4-hydroxybutyryl-coa (4-hb-coa) to crotonyl coa. the enzyme contains one [4fe-4s](2+) cluster and one flavin adenine dinucleotide (fad) molecule per homotetramer. incubation of the enzyme with its substrate under equilibrium conditions followed by freezing at 77k induced the epr-spectrum of a neutral flavin semiquinone (g=2.005, linewidth 2.1 mt), while at 10k additional signals ... | 2005 | 15668183 |
| electron-nuclear double resonance spectroscopy investigation of 4-hydroxybutyryl-coa dehydratase from clostridium aminobutyricum: comparison with other flavin radical enzymes. | a fad and [4fe-4s]cluster-containing enzyme from clostridium aminobutyricum catalyses the reversible dehydration of 4-hydroxybutyryl-coa to crotonyl-coa which involves the cleavage of an unactivated c-h bond at the beta-carbon. transient oxidation of the substrate to an enoxy radical by fad might facilitate the removal of this beta-proton, whereas no function could be attributed to the [4fe-4s]cluster. in this paper the organic radical, which is formed by partial reduction of the enzyme with dit ... | 1997 | 9377480 |
| metabolism of omega-amino acids. iv. gamma aminobutyrate fermentation by cell-free extracts of clostridium aminobutyricum. | | 1963 | 13952770 |
| metabolism of amega-amino acids. iii. mechanism of conversion of gamma-aminobutyrate to gamma-hydroxybutryate by clostridium aminobutyricum. | | 1963 | 13952769 |
| assay of 4-hydroxybutyryl-coa dehydratase from clostridium aminobutyricum. | it has been proposed that clostridium aminobutyricum contains an enzyme catalyzing an unusual reaction: the dehydration of 4-hydroxybutyryl-coa to vinylacetyl-coa. 4-hydroxy-[3-3h]butyric acid has been prepared which allows the activity of this enzyme to be assayed in the presence of acetyl-coa under anaerobic conditions by the release of tritiated water. initial characterization of the enzyme from c. aminobutyricum has shown it to be largely membrane or particle bound in the crude lysates. it c ... | 1990 | 2227355 |
| fermentation of 4-aminobutyrate by clostridium aminobutyricum: cloning of two genes involved in the formation and dehydration of 4-hydroxybutyryl-coa. | clostridium aminobutyricum ferments 4-aminobutyrate via succinic semialdehyde, 4-hydroxybutyrate, 4-hydroxybutyryl-coa and crotonyl-coa to acetate and butyrate. the genes coding for the enzymes that catalyse the interconversion of these intermediates are arranged in the order abfd (4-hydroxybutyryl-coa dehydratase), abft (4-hydroxybutyrate coa-transferase), and abfh (nad-dependent 4-hydroxybutyrate dehydrogenase). the genes abfd and abft were cloned, sequenced and expressed as active enzymes in ... | 2000 | 11041350 |
| crystal structure of the complex between 4-hydroxybutyrate coa-transferase from clostridium aminobutyricum and coa. | clostridium aminobutyricum ferments 4-aminobutyrate (+¦-aminobutyrate, gaba) to ammonia, acetate and butyrate via 4-hydroxybutyrate that is activated to the coa-thioester catalyzed by 4-hydroxybutyrate coa-transferase. then, 4-hydroxybutyryl-coa is dehydrated to crotonyl-coa, which disproportionates to butyryl-coa and acetyl-coa. cocrystallization of the coa-transferase with the alternate substrate butyryl-coa yielded crystals with non-covalently bound coa and two water molecules at the active s ... | 2011 | 21833509 |
| 4-hydroxybutyryl-coa dehydratase from clostridium aminobutyricum: characterization of fad and iron-sulfur clusters involved in an overall non-redox reaction. | 4-hydroxybutyryl-coa dehydratase catalyzes the reversible dehydration of 4-hydroxybutyryl-coa to crotonyl-coa, which involves cleavage of an unactivated beta-c-h bond. the enzyme also catalyzes the apparently irreversible isomerization of vinylacetyl-coa to crotonyl-coa. addition of crotonyl-coa to the dehydratase, which contains fad as well as non-heme iron and acid labile sulfur, led to a decrease of the flavin absorbance at 438 nm and an increase in the region from 500 to 800 nm. the protein- ... | 1996 | 8794752 |
| purification and properties of 4-hydroxybutyrate coenzyme a transferase from clostridium aminobutyricum. | a new coenzyme a (coa)-transferase from the anaerobe clostridium aminobutyricum catalyzing the formation of 4-hydroxybutyryl-coa from 4-hydroxybutyrate and acetyl-coa is described. the enzyme was purified to homogeneity by standard techniques, including fast protein liquid chromatography under aerobic conditions. its molecular mass was determined to be 110 kda, and that of the only subunit was determined to be 54 kda, indicating a homodimeric structure. besides acetate and acetyl-coa, the follow ... | 1991 | 1768145 |
| mössbauer study of 4-hydroxybutyryl-coa dehydratase--probing the role of an iron-sulfur cluster in an overall non-redox reaction. | 4-hydroxybutyryl-coa dehydratase from clostridium aminobutyricum catalyzes the dehydration of 4-hydroxybutyryl-coa to crotonyl-coa. although dehydration is an overall non-redox reaction, the enzyme contains fad and fe-s clusters. previous work has shown that the fe-s clusters are difficult to reduce and therefore unlikely to be redox-active in catalysis. here, mössbauer spectroscopy has been used to characterise the fe-s clusters in active as well as in air-inactivated enzyme. in zero magnetic f ... | 1997 | 9346292 |
| crystal structure of 4-hydroxybutyrate coa-transferase from clostridium aminobutyricum. | 4-hydroxybutyrate coa-transferases (4-hb-coat) takes part in the fermentation of 4-aminobutyrate to ammonia, acetate, and butyrate in anaerobic bacteria such as clostridium aminobutyricum and porphyromonas gingivalis or facultative anaerobic bacteria such as shewanella oneidensis. site-directed mutagenesis of the highly active enzyme has identified the catalytic glutamate residue as e238. crystal structure of this enzyme has been determined at a resolution of 1.85 a. the 438-amino acid residue p ... | 2009 | 19804364 |
| isolation of the exoelectrogenic denitrifying bacterium comamonas denitrificans based on dilution to extinction. | the anode biofilm in a microbial fuel cell (mfc) is composed of diverse populations of bacteria, many of whose capacities for electricity generation are unknown. to identify functional populations in these exoelectrogenic communities, a culture-dependent approach based on dilution to extinction was combined with culture-independent community analysis. we analyzed the diversity and dynamics of microbial communities in single-chamber air-cathode mfcs with different anode surfaces using denaturing ... | 2010 | 19779712 |
| molecular diversity of bacteria in yunnan yellow cattle (bos taurs) from nujiang region, china. | the rumen content of four yunnan yellow cattle (bos taurs) were collected to determine the bacteria diversity by using 16s rrna gene sequence analysis. a total of 129 sequences were examined and the sequences were referred as 107 otu (operational taxonomy unit) according to the similarity level of 97% in gene sequence. similarity analysis revealed that yunnan yellow cattle had 12 sequences (10 otu) shared 97% or greater similarity with cultured rumen bacteria butyrivibrio fibrisolvens, succinicl ... | 2011 | 21598111 |
| metabolism of omega-amino acids. v. energetics of the gamma-aminobutyrate fermentation by clostridium aminobutyricum. | hardman, john k. (national heart institute, national institutes of health, bethesda, md.) and thressa c. stadtman. metabolism of omega-amino acids. v. energetics of the gamma-aminobutyrate fermentation by clostridium aminobutyricum. j. bacteriol. 85:1326-1333. 1963.-clostridium aminobutyricum utilizes gamma-aminobutyrate as its sole carbon, nitrogen, and energy source, producing ammonia, acetate, and butyrate as a result of this fermentation. coenzyme a (coa)-transferase, phosphotransacetylase, ... | 1963 | 14047225 |
| purification and properties of an iron-sulfur and fad-containing 4-hydroxybutyryl-coa dehydratase/vinylacetyl-coa delta 3-delta 2-isomerase from clostridium aminobutyricum. | 4-hydroxybutyryl-coa dehydratase, the key enzyme in the metabolism of gamma-aminobutyrate in clostridium aminobutyricum, represents approximately 15-25% of the soluble protein. the enzyme was purified to homogeneity under anaerobic conditions to a specific activity of 209 nkat mg-1. the dehydratase catalyses the reversible conversion of 4-hydroxybutyryl-coa (km = 50 microm) to crotonyl-coa and possesses a probably intrinsic vinylacetyl-coa delta 3-delta 2-isomerase with a specific activity of 22 ... | 1993 | 8344309 |
| metabolism of omega-amino acids. i. fermentation of gamma-aminobutyric acid by clostridium aminobutyricum n. sp. | | 1960 | 14399736 |
| identification and detection of prokaryotic symbionts in the ciliate metopus from anaerobic granular sludge. | the aim of the present study was to investigate the prokaryotic community structure of the anaerobic ciliate, metopus sp. using rrna sequencing, fluorescence in situ hybridization (fish), and transmission electron microscopy (tem). metopus sp. was physically separated from anaerobic granular sludge in a domestic wastewater treatment plant and anoxically cultivated for 7 d. 16s rrna gene sequences from the prokaryotes methanoregula boonei and clostridium aminobutyricum were abundantly detected in ... | 2015 | 26639580 |
| succinate-ethanol fermentation in clostridium kluyveri: purification and characterisation of 4-hydroxybutyryl-coa dehydratase/vinylacetyl-coa delta 3-delta 2-isomerase. | anaerobically prepared cell extracts of clostridium kluyveri grown on succinate plus ethanol contained high amounts of 4-hydroxybutyryl-coa dehydratase, which catalyzes the reversible dehydration of 4-hydroxybutyryl-coa to crotonyl-coa. the enzyme was purified 12-fold under strictly anaerobic conditions to over 95% homogeneity and had a specific activity of 123 nkat mg-1. the finding of this dehydratase means that all of the enzymes necessary for fermentation of succinate plus ethanol by c. kluy ... | 1994 | 8161284 |
| substrate-induced radical formation in 4-hydroxybutyryl coenzyme a dehydratase from clostridium aminobutyricum. | 4-hydroxybutyryl-coenzyme a (coa) dehydratase (4hbd) from clostridium aminobutyricum catalyzes the reversible dehydration of 4-hydroxybutyryl-coa to crotonyl-coa and the irreversible isomerization of vinylacetyl-coa to crotonyl-coa. 4hbd is an oxygen-sensitive homotetrameric enzyme with one [4fe-4s](2+) cluster and one flavin adenine dinucleotide (fad) in each subunit. upon the addition of crotonyl-coa or the analogues butyryl-coa, acetyl-coa, and coa, uv-visible light and electron paramagnetic ... | 2015 | 25452282 |