Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:Q16795 (ubiquinone)
 5,455 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The genus Trichosporon was revised using characters of morphology, ultrastructure, physiology, ubiquinone systems, mol% G + C of DNA, DNA/DNA reassociations and 26S ribosomal RNA partial sequences. A total of 101 strains was used, including all available type and authentic cultures of previously described taxa. Nineteen taxa could be distinguished, 15 of which having Q-9 coenzyme systems and 4 having Q-10. Sixteen previously described names were reduced to synonymy. One new species was described. The genus is characterized by the presence of arthroconidia. Few species possess further diagnostic morphological characters, such as the presence of appressoria, macroconidia or meristematic conidiation. The septa of two species were found to be non-perforate, while those of the remaining species contained dolipores at variable degrees of differentiation, with or without vesicular or tubular parenthesomes. All species were able to assimilate a large number of carbon compounds; visible CO2 production was absent. The genus was found to be fairly homogeneous on the basis of a phylogenetic analysis of partial 26S rRNA sequences, with the exception of T. pullulans which proved to be unrelated. Most taxa were found to occupy well-defined ecological niches. Within the group of taxa isolated from humans, a distinction could be made between those involved in systemic mycoses and those which mainly caused pubic or non-pubic white piedras, respectively. One species was consistently associated with animals, while others came mainly from soil or water. One species was mesophilic and another psychrophilic.
 ...
PMID:Contributions to a revision of the genus Trichosporon. 149 34

Citrate is fermented by Klebsiella pneumoniae to 2 acetate, 0.5 formate and 1.2 CO2. The formation of less than 1 formate and greater than 1 CO2 per citrate can be accounted for by the oxidation of formate to CO2 in order to provide reducing equivalents for the assimilation of citrate into cell carbon. A membrane-bound electron transport chain is apparently involved in NADH synthesis by these cells. The electrons from formate oxidation to CO2 are used to reduce ubiquinone to ubiquinol by membrane-bound formate dehydrogenase and ubiquinol further delivers its electrons to NAD+, if this endergonic reaction is powered by delta mu Na+. The endogenous NADH level of K. pneumoniae cells thus increased in the presence of formate in response to a delta pNa+ greater than -100 mV. NADH formation was completely abolished in the presence of oxygen or after addition of hydroxyquinoline-N-oxide, a specific inhibitor of the Na(+)-translocating NADH:ubiquinone oxidoreductase. The increase of endogenous NADH was dependent on the delta pNa+ applied to the cells. Inverted membrane vesicles of K. pneumoniae catalysed the reduction of NAD+ to NADH with formate as electron donor after application of delta mu Na+ of about 120 mV consisting of delta pNa+ of 60 mV and delta psi of the same magnitude. Neither the delta pNa+ nor the delta psi of this size alone was sufficient to drive the endergonic reaction. Strictly anaerobic conditions were required for NADH formation and hydroxyquinoline-N-oxide completely inactivated the reaction.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:NADH formation by Na(+)-coupled reversed electron transfer in Klebsiella pneumoniae. 150 43

Pyruvate oxidase is a flavoprotein dehydrogenase isolated from Escherichia coli which catalyzes the oxidative decarboxylation of pyruvate to acetate and CO2. In vivo, the enzyme can bind to the bacterial membrane and reduce ubiquinone-8, feeding electrons into the respiratory chain. The purified enzyme has been shown previously to bind to phospholipids and detergents and, upon doing so, is activated. The turnover with ferricyanide as an electron acceptor increases 20- to 30-fold upon lipid binding. In this work, initial velocity and stop-flow kinetics are used to investigate the activation of this enzyme. It is shown that the unactivated form of the enzyme is markedly hysteretic. Progress curves at low substrate concentrations show an initial acceleration in enzyme turnover. This is consistent with the results of stop-flow experiments. Rates obtained for either the reduction of the unactivated flavoprotein by pyruvate or its reoxidation by ferricyanide in single turnover experiments are much slower than the rates predicted by observed turnover in initial velocity studies, in some cases by more than 2 orders of magnitude. The data are best explained by the slow interconversion between two forms of the enzyme, one with low turnover and one which rapidly turns over. As isolated, the enzyme is highly unreactive, as revealed by the stop-flow experiments. During turnover, even in the absence of lipid activators, some of the enzyme converts to the rapid-turnover form. This slow interconversion is shown by kinetic simulation to preclude a steady state from being established. Lipid activators appear to shift the equilibrium to favor the rapid-turnover form of the enzyme. Once the enzyme is "locked" into an activated conformation, the hysteresis is no longer observed, and the stop-flow results are in agreement with data obtained from initial velocity experiments. Activation appears to result in both increased rates of electron transfer into and out of the flavin.
 ...
PMID:Kinetic studies of the lipid-activated pyruvate oxidase flavoprotein of Escherichia coli. 390 8

The pattern of incorporation of radioactivity from [1-14C]acetate and [2-14C]acetate into the polyprenyl side-chain of ubiquinones in bacteria (Azotobacter vinelandii, Pseudomonas sesami, Escherichia coli and Rhodopseudomonas capsulata) was studied. For this purpose, a new degradation method involving a modified Barbier-Wieland reaction of laevulinic acid was developed, and used along with the iodoform reaction. Both C-1 and C-2 of acetate were incorporated exclusively into C-2 of laevulinic acid suggesting that the well-known pathway through acetoacetyl-CoA ('acetoacetate pathway') was not operative in these bacteria. An alternative pathway ('acetolactate pathway'), starting with pyruvate and acetaldehyde as the distal precursors, and utilizing the reactions of leucine and valine metabolism, was postulated. It was also postulated that C-1 of acetate is incorporated not directly, but after oxidation to CO2. The pattern of incorporation of radioactivity from [U-14C]valine, [U-14C]alanine and NaH14CO3 into the side-chain of ubiquinone of R. capsulata was in agreement with the operation of the 'acetolactate pathway'.
 ...
PMID:An alternative pathway for the biosynthesis of isoprenoid compounds in bacteria. 627 17

Zymobacter palmae gen. nov., sp. nov. was proposed for a new ethanol-fermenting bacterium that was isolated from palm sap in Okinawa Prefecture, Japan. The bacterium is gram-negative, facultatively anaerobic, catalase-positive, oxidase-negative, nonsporeforming and peritrichously flagellated. It requires nicotinic acid for growth. It ferments hexoses, alpha-linked di- and tri-saccharides, and sugar alcohols (fructose, galactose, glucose, mannose, maltose, melibiose, saccharose, raffinose, mannitol and sorbitol). Fifteen percent of maltose in broth medium is effectively fermented, whereas glucose with a concentration higher than 10% delayed growth initiation and decreased growth rates. Maltose is fermented to produce ethanol and CO2 with a trace amount of acids. Approximately 2 mol of ethanol are produced from 1 mol moiety of hexose of maltose. The organism possesses ubiquinone-9. The G + C content of the DNA is 55.8 +/- 0.4 mol%. Major cellular fatty acids were palmitic and oleic acids and cyclopropanic acid of C19:0. Characteristic hydroxylated acid was 3-hydroxy dodecanoic acid. The bacterium is distinct from other ethanol-fermenting bacteria belonging to the genera Zymomonas Kluyver and van Niel 1936 and Saccharobacter Yaping et al. 1990 with respect to chemotaxonomic and other phenotypic characters to warrant to compose a new genus and a new species. The type strain is strain T109 (= IAM 14233).
 ...
PMID:Zymobacter palmae gen. nov., sp. nov., a new ethanol-fermenting peritrichous bacterium isolated from palm sap. 825 79

Free radical formation in aqueous solutions of ubiquinone (coenzyme Qo) induced by ultrasound was studied by EPR and spin trapping with 3,5-dibromo-4-nitrosobenzene sulphonate. When aqueous solutions of ubiquinone were sonicated with 50-kHz ultrasound in the presence of argon or nitrogen, radicals formed by addition of.OH or.H to the double bonds of the ubiquinone ring and methyl radicals were observed as the major spin adducts. The methyl radicals were formed by pyrolysis of ubiquinone. These radicals led to the degradation of ubiquinone. The reduced from of ubiquinone, ubiquinol, was formed by sonication in the presence of argon, and its formation was prevented by addition of native but not of denatured superoxide dismutase. Sodium formate, which scavenges .OH to form CO2-., enhanced ubiquinol formation but partially inhibited the degradation of the ubiquinone ring. No ubiquinol was formed in nitrogen- or oxygen-saturated solutions under our conditions. These results indicate that ubiquinol was formed by reduction of ubiquinone by O2-., which was generated by the sonolysis of argon-saturated water.
 ...
PMID:Sonolysis of ubiquinone in aqueous solutions. An EPR spin-trapping study. 860 50

Strain GB isolated from the maize rhizosphere is a gram-negative, aerobic, non-spore-forming, nonpigmented, nonmotile, chemolithotrophic, facultatively methylotrophic bacterium. Cells are cocci or short rods. The strain does not require vitamins. Optimum growth in a medium with methanol occurs at 38-42 degrees C at pH 8.0-9.2. The doubling time is 12 h. In addition to methanol, the bacterium can grow on methylamine, dimethylformamide, acetone, thiosulfate + NaHCO3, and in an atmosphere of H2 + CO2 + O2. Methanol and methylamine are oxidized by the respective dehydrogenases to CO2 via formaldehyde and formate, respectively. The CO2 produced is assimilated via the ribulose bisphosphate pathway. Fatty acids are dominated by cyclopropanoic (58-61%), palmitic (24-26%), and octadecanoic (8-9%) acids. The main phospholipids are phosphatidylglycerol, phosphatidylethanolamine, and phosphatidylcholine. The major ubiquinone is Q10. The bacterial genome contains genes controlling the synthesis and secretion of cytokinins. The culture liquid exhibits cytokinin activity. The G + C content of DNA is 62.5 mol %, as determined from the DNA thermal denaturation temperature (Tm). Strain GB shows a moderate degree of DNA-DNA homology (< 40%) with the type representatives of the genus Paracoccus. Based on the data obtained, the bacterium was classified as a new species of this genus, named P. kondratievae.
 ...
PMID:[A novel plant-associated thermotolerant alkalophilic methylotroph of the genus Paracoccus]. 1131 75

A novel thermophilic hydrogen-oxidizing bacterium, Hydrogenophilus hirschii Yel5aT (= DSM 11420T = JCM 10831T) has been isolated from the Angel Terrace Spring, Yellowstone National Park. The isolate was rod-shaped (1.0-1.5 x 0.8 microm) with a polarly inserted flagellum. Cells grew chemolithoautotrophically under an atmosphere of H2 and CO2 (80:20) in the presence of low concentrations of O2 (optimum 2.5%). Organotrophic growth occurred on complex organic substrates such as yeast extract and peptone and on organic acids. Carbohydrates and amino acids were not utilized. The strain grew between 50 and 67 degrees C; optimal growth occurred at a temperature of 63 degrees C. The pH optimum was 6.5. NaCl inhibited growth at concentrations higher than 1.5%. The major respiratory lipoquinone was ubiquinone-8. Analysis of fatty acids of Yel5aT revealed a straight-chain saturated C16:0 as the major component followed by cyclo C17:0 and cyclo C19:0. The G+C content of total DNA was 61 mol%. Phylogenetic analysis placed the strain in the beta-proteobacteria. The 16S rDNA sequence of strain Yel5aT was related to that of Hydrogenophilus thermoluteolus. To our knowledge, Hydrogenophilus hirschii is the most thermophilic micro-organism found within the proteobacteria that grows in the temperature range 50-68 degrees C.
 ...
PMID:Hydrogenophilus hirschii sp. nov., a novel thermophilic hydrogen-oxidizing beta-proteobacterium isolated from Yellowstone National Park. 1132 Oct 94

A novel genus, Albibacter, with one species, Albibacter methylovorans sp. nov., is proposed for a facultatively chemolithotrophic and methylotrophic bacterium (strain DM10T) with the ribulose bisphosphate (RuBP) pathway of C1 assimilation. The bacterium is a Gram-negative, aerobic, asporogenous, nonmotile, colourless rod that multiplies by binary fission. The organism utilizes dichloromethane, methanol, methylamine, formate and CO2/H2, as well as a variety of polycarbon compounds, as carbon and energy sources. It is neutrophilic and mesophilic. The major cellular fatty acids are straight-chain unsaturated C18:1, saturated C16:0 and cyclopropane C19:0 acids. The main ubiquinone is Q-10. The dominant phospholipids are phosphatidyl ethanolamine, phosphatidyl glycerol, phosphatidyl choline and cardiolipin. The DNA G+C content is 66.7 mol%. Strain DM10T has a very low degree of DNA-DNA hybridization (4-7%) with the type species of the genera Paracoccus, Xanthobacter, Blastobacter, Angulomicrobium, Ancylobacter and Ralstonia of RuBP pathway methylobacteria. Another approach, involving comparative 16S rDNA analysis, has shown that the novel isolate represents a separate branch within the alpha-2 subgroup of the Proteobacteria. The type species of the new genus is Albibacter methylovorans sp. nov.; the type strain is DM10T (= VKM B-2236T = DSM 13819T).
 ...
PMID:Albibacter methylovorans gen. nov., sp. nov., a novel aerobic, facultatively autotrophic and methylotrophic bacterium that utilizes dichloromethane. 1141 73

Twenty-one bacterial associations isolated from the soda lakes of the southern Transbaikal region were found to be able to actively grow at pH 9-10 on methanol as the source of carbon and energy. Two alkalitolerant facultatively methylotrophic strains, Bur 3 and Bur 5, were obtained in pure cultures. Both strains represent gram-negative, nonmotile, bean-shaped, encapsulated cells that reproduce by binary fission. The strains are able to grow at temperatures ranging from 6 to 42 degrees C, with an optimum growth temperature of 25-29 degrees C (strain Bur 3) and 35-37 degrees C (strain Bur 5) and at pH between 6.5 and 9.5, with an optimum pH value of 8.0-8.5. At pH 9.0, strain Bur 3 exhibits an increased content of phosphatidylglycerol and a decreased content of phosphatidylethanolamine. Strains Bur 3 and Bur 5 are similar in the G + C content of their DNAs (66.2 and 65.5 mol %, respectively) and in the type of the dominant ubiquinone (Q10). Unlike Bur 5, strain Bur 3 is able to grow autotrophically in an atmosphere of CO2 + O2 + H2. The strains oxidize, by the respective dehydrogenases, methanol to CO2, which is assimilated via the ribulose bisphosphate pathway. Ammonium ions are assimilated in the glutamate cycle and by the reductive amination of alpha-ketoglutarate. The strains are highly homologous to each other (92%) and are much less homologous (at a level of 28-35%) to representatives of the genus Ancylobacter, A. aquaticus ATCC 25396T and A. vacuolatum DSM 1277. Based on the results obtained, both strains are assigned to a new species, Ancylobacter natronum sp. nov.
 ...
PMID:[New aerobic methyltrophic isolates from the Soda lakes of the southern Transbaikal]. 1145 Apr 64


1 2 Next >>